diff --git a/src/wp-admin/includes/class-wp-filesystem-base.php b/src/wp-admin/includes/class-wp-filesystem-base.php
index c518408ec9..45e4474767 100644
--- a/src/wp-admin/includes/class-wp-filesystem-base.php
+++ b/src/wp-admin/includes/class-wp-filesystem-base.php
@@ -7,11 +7,12 @@
  */
 
 /**
- * Base WordPress Filesystem class for which Filesystem implementations extend
+ * Base WordPress Filesystem class which Filesystem implementations extend.
  *
  * @since 2.5.0
  */
 class WP_Filesystem_Base {
+
 	/**
 	 * Whether to display debug data for the connection.
 	 *
@@ -46,7 +47,7 @@ class WP_Filesystem_Base {
 	public $options = array();
 
 	/**
-	 * Return the path on the remote filesystem of ABSPATH.
+	 * Returns the path on the remote filesystem of ABSPATH.
 	 *
 	 * @since 2.7.0
 	 *
@@ -62,7 +63,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Return the path on the remote filesystem of WP_CONTENT_DIR.
+	 * Returns the path on the remote filesystem of WP_CONTENT_DIR.
 	 *
 	 * @since 2.7.0
 	 *
@@ -73,7 +74,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Return the path on the remote filesystem of WP_PLUGIN_DIR.
+	 * Returns the path on the remote filesystem of WP_PLUGIN_DIR.
 	 *
 	 * @since 2.7.0
 	 *
@@ -84,11 +85,12 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Return the path on the remote filesystem of the Themes Directory.
+	 * Returns the path on the remote filesystem of the Themes Directory.
 	 *
 	 * @since 2.7.0
 	 *
-	 * @param string $theme The Theme stylesheet or template for the directory.
+	 * @param string|false $theme Optional. The theme stylesheet or template for the directory.
+	 *                            Default false.
 	 * @return string The location of the remote path.
 	 */
 	public function wp_themes_dir( $theme = false ) {
@@ -103,7 +105,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Return the path on the remote filesystem of WP_LANG_DIR.
+	 * Returns the path on the remote filesystem of WP_LANG_DIR.
 	 *
 	 * @since 3.2.0
 	 *
@@ -114,7 +116,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Locate a folder on the remote filesystem.
+	 * Locates a folder on the remote filesystem.
 	 *
 	 * @since 2.5.0
 	 * @deprecated 2.7.0 use WP_Filesystem::abspath() or WP_Filesystem::wp_*_dir() instead.
@@ -136,7 +138,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Locate a folder on the remote filesystem.
+	 * Locates a folder on the remote filesystem.
 	 *
 	 * @since 2.5.0
 	 * @deprecated 2.7.0 use WP_Filesystem::abspath() or WP_Filesystem::wp_*_dir() methods instead.
@@ -157,10 +159,10 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Locate a folder on the remote filesystem.
+	 * Locates a folder on the remote filesystem.
 	 *
 	 * Assumes that on Windows systems, Stripping off the Drive
-	 * letter is OK Sanitizes \\ to / in windows filepaths.
+	 * letter is OK Sanitizes \\ to / in Windows filepaths.
 	 *
 	 * @since 2.7.0
 	 *
@@ -229,7 +231,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Locate a folder on the remote filesystem.
+	 * Locates a folder on the remote filesystem.
 	 *
 	 * Expects Windows sanitized path.
 	 *
@@ -267,9 +269,9 @@ class WP_Filesystem_Base {
 			/*
 			 * Working from /home/ to /user/ to /wordpress/ see if that file exists within
 			 * the current folder, If it's found, change into it and follow through looking
-			 * for it. If it cant find WordPress down that route, it'll continue onto the next
+			 * for it. If it can't find WordPress down that route, it'll continue onto the next
 			 * folder level, and see if that matches, and so on. If it reaches the end, and still
-			 * cant find it, it'll return false for the entire function.
+			 * can't find it, it'll return false for the entire function.
 			 */
 			if ( isset( $files[ $key ] ) ) {
 
@@ -311,7 +313,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Return the *nix-style file permissions for a file.
+	 * Returns the *nix-style file permissions for a file.
 	 *
 	 * From the PHP documentation page for fileperms().
 	 *
@@ -366,18 +368,19 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Gets the permissions of the specified file or filepath in their octal format
+	 * Gets the permissions of the specified file or filepath in their octal format.
 	 *
 	 * @since 2.5.0
-	 * @param string $file
-	 * @return string the last 3 characters of the octal number
+	 *
+	 * @param string $file Path to the file.
+	 * @return string Mode of the file (the last 3 digits).
 	 */
 	public function getchmod( $file ) {
 		return '777';
 	}
 
 	/**
-	 * Convert *nix-style file permissions to a octal number.
+	 * Converts *nix-style file permissions to a octal number.
 	 *
 	 * Converts '-rw-r--r--' to 0644
 	 * From "info at rvgate dot nl"'s comment on the PHP documentation for chmod()
@@ -417,187 +420,192 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Determine if the string provided contains binary characters.
+	 * Determines if the string provided contains binary characters.
 	 *
 	 * @since 2.7.0
 	 *
 	 * @param string $text String to test against.
-	 * @return bool true if string is binary, false otherwise.
+	 * @return bool True if string is binary, false otherwise.
 	 */
 	public function is_binary( $text ) {
 		return (bool) preg_match( '|[^\x20-\x7E]|', $text ); // chr(32)..chr(127)
 	}
 
 	/**
-	 * Change the ownership of a file / folder.
+	 * Changes the owner of a file or directory.
 	 *
 	 * Default behavior is to do nothing, override this in your subclass, if desired.
 	 *
 	 * @since 2.5.0
 	 *
-	 * @param string $file      Path to the file.
-	 * @param mixed  $owner     A user name or number.
-	 * @param bool   $recursive Optional. If set True changes file owner recursivly. Defaults to False.
-	 * @return bool Returns true on success or false on failure.
+	 * @param string     $file      Path to the file or directory.
+	 * @param string|int $owner     A user name or number.
+	 * @param bool       $recursive Optional. If set to true, changes file owner recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chown( $file, $owner, $recursive = false ) {
 		return false;
 	}
 
 	/**
-	 * Connect filesystem.
+	 * Connects filesystem.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @return bool True on success or false on failure (always true for WP_Filesystem_Direct).
+	 * @return bool True on success, false on failure (always true for WP_Filesystem_Direct).
 	 */
 	public function connect() {
 		return true;
 	}
 
 	/**
-	 * Read entire file into a string.
+	 * Reads entire file into a string.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
 	 * @param string $file Name of the file to read.
-	 * @return mixed|bool Returns the read data or false on failure.
+	 * @return string|false Read data on success, false on failure.
 	 */
 	public function get_contents( $file ) {
 		return false;
 	}
 
 	/**
-	 * Read entire file into an array.
+	 * Reads entire file into an array.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
 	 * @param string $file Path to the file.
-	 * @return array|bool the file contents in an array or false on failure.
+	 * @return array|false File contents in an array on success, false on failure.
 	 */
 	public function get_contents_array( $file ) {
 		return false;
 	}
 
 	/**
-	 * Write a string to a file.
+	 * Writes a string to a file.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file     Remote path to the file where to write the data.
-	 * @param string $contents The data to write.
-	 * @param int    $mode     Optional. The file permissions as octal number, usually 0644.
-	 * @return bool False on failure.
+	 * @param string    $file     Remote path to the file where to write the data.
+	 * @param string    $contents The data to write.
+	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function put_contents( $file, $contents, $mode = false ) {
 		return false;
 	}
 
 	/**
-	 * Get the current working directory.
+	 * Gets the current working directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @return string|bool The current working directory on success, or false on failure.
+	 * @return string|false The current working directory on success, false on failure.
 	 */
 	public function cwd() {
 		return false;
 	}
 
 	/**
-	 * Change current directory.
+	 * Changes current directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
 	 * @param string $dir The new current directory.
-	 * @return bool|string
+	 * @return bool True on success, false on failure.
 	 */
 	public function chdir( $dir ) {
 		return false;
 	}
 
 	/**
-	 * Change the file group.
+	 * Changes the file group.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file      Path to the file.
-	 * @param mixed  $group     A group name or number.
-	 * @param bool   $recursive Optional. If set True changes file group recursively. Defaults to False.
-	 * @return bool|string
+	 * @param string     $file      Path to the file.
+	 * @param string|int $group     A group name or number.
+	 * @param bool       $recursive Optional. If set to true, changes file group recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chgrp( $file, $group, $recursive = false ) {
 		return false;
 	}
 
 	/**
-	 * Change filesystem permissions.
+	 * Changes filesystem permissions.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file      Path to the file.
-	 * @param int    $mode      Optional. The permissions as octal number, usually 0644 for files, 0755 for dirs.
-	 * @param bool   $recursive Optional. If set True changes file group recursively. Defaults to False.
-	 * @return bool|string
+	 * @param string    $file      Path to the file.
+	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,
+	 *                             0755 for directories. Default false.
+	 * @param bool      $recursive Optional. If set to true, changes file group recursively.
+	 *                             Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chmod( $file, $mode = false, $recursive = false ) {
 		return false;
 	}
 
 	/**
-	 * Get the file owner.
+	 * Gets the file owner.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
 	 * @param string $file Path to the file.
-	 * @return string|bool Username of the user or false on error.
+	 * @return string|false Username of the owner on success, false on failure.
 	 */
 	public function owner( $file ) {
 		return false;
 	}
 
 	/**
-	 * Get the file's group.
+	 * Gets the file's group.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
 	 * @param string $file Path to the file.
-	 * @return string|bool The group or false on error.
+	 * @return string|false The group on success, false on failure.
 	 */
 	public function group( $file ) {
 		return false;
 	}
 
 	/**
-	 * Copy a file.
+	 * Copies a file.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $source      Path to the source file.
-	 * @param string $destination Path to the destination file.
-	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
-	 *                            Default false.
-	 * @param int    $mode        Optional. The permissions as octal number, usually 0644 for files, 0755 for dirs.
-	 *                            Default false.
-	 * @return bool True if file copied successfully, False otherwise.
+	 * @param string    $source      Path to the source file.
+	 * @param string    $destination Path to the destination file.
+	 * @param bool      $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                               Default false.
+	 * @param int|false $mode        Optional. The permissions as octal number, usually 0644 for files,
+	 *                               0755 for dirs. Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
 		return false;
 	}
 
 	/**
-	 * Move a file.
+	 * Moves a file.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -606,36 +614,36 @@ class WP_Filesystem_Base {
 	 * @param string $destination Path to the destination file.
 	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
 	 *                            Default false.
-	 * @return bool True if file copied successfully, False otherwise.
+	 * @return bool True on success, false on failure.
 	 */
 	public function move( $source, $destination, $overwrite = false ) {
 		return false;
 	}
 
 	/**
-	 * Delete a file or directory.
+	 * Deletes a file or directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file      Path to the file.
-	 * @param bool   $recursive Optional. If set True changes file group recursively. Defaults to False.
-	 *                          Default false.
-	 * @param bool   $type      Type of resource. 'f' for file, 'd' for directory.
-	 *                          Default false.
-	 * @return bool True if the file or directory was deleted, false on failure.
+	 * @param string       $file      Path to the file or directory.
+	 * @param bool         $recursive Optional. If set to true, changes file group recursively.
+	 *                                Default false.
+	 * @param string|false $type      Type of resource. 'f' for file, 'd' for directory.
+	 *                                Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function delete( $file, $recursive = false, $type = false ) {
 		return false;
 	}
 
 	/**
-	 * Check if a file or directory exists.
+	 * Checks if a file or directory exists.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file Path to file/directory.
+	 * @param string $file Path to file or directory.
 	 * @return bool Whether $file exists or not.
 	 */
 	public function exists( $file ) {
@@ -643,7 +651,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Check if resource is a file.
+	 * Checks if resource is a file.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -656,7 +664,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Check if resource is a directory.
+	 * Checks if resource is a directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -669,7 +677,7 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Check if a file is readable.
+	 * Checks if a file is readable.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -682,12 +690,12 @@ class WP_Filesystem_Base {
 	}
 
 	/**
-	 * Check if a file or directory is writable.
+	 * Checks if a file or directory is writable.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $file Path to file.
+	 * @param string $file Path to file or directory.
 	 * @return bool Whether $file is writable.
 	 */
 	public function is_writable( $file ) {
@@ -701,7 +709,7 @@ class WP_Filesystem_Base {
 	 * @abstract
 	 *
 	 * @param string $file Path to file.
-	 * @return int|bool Unix timestamp representing last access time.
+	 * @return int|false Unix timestamp representing last access time, false on failure.
 	 */
 	public function atime( $file ) {
 		return false;
@@ -714,7 +722,7 @@ class WP_Filesystem_Base {
 	 * @abstract
 	 *
 	 * @param string $file Path to file.
-	 * @return int|bool Unix timestamp representing modification time.
+	 * @return int|false Unix timestamp representing modification time, false on failure.
 	 */
 	public function mtime( $file ) {
 		return false;
@@ -727,14 +735,14 @@ class WP_Filesystem_Base {
 	 * @abstract
 	 *
 	 * @param string $file Path to file.
-	 * @return int|bool Size of the file in bytes.
+	 * @return int|false Size of the file in bytes on success, false on failure.
 	 */
 	public function size( $file ) {
 		return false;
 	}
 
 	/**
-	 * Set the access and modification times of a file.
+	 * Sets the access and modification times of a file.
 	 *
 	 * Note: If $file doesn't exist, it will be created.
 	 *
@@ -746,33 +754,33 @@ class WP_Filesystem_Base {
 	 *                      Default 0.
 	 * @param int    $atime Optional. Access time to set for file.
 	 *                      Default 0.
-	 * @return bool Whether operation was successful or not.
+	 * @return bool True on success, false on failure.
 	 */
 	public function touch( $file, $time = 0, $atime = 0 ) {
 		return false;
 	}
 
 	/**
-	 * Create a directory.
+	 * Creates a directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
 	 *
-	 * @param string $path  Path for new directory.
-	 * @param mixed  $chmod Optional. The permissions as octal number, (or False to skip chmod)
-	 *                      Default false.
-	 * @param mixed  $chown Optional. A user name or number (or False to skip chown)
-	 *                      Default false.
-	 * @param mixed  $chgrp Optional. A group name or number (or False to skip chgrp).
-	 *                      Default false.
-	 * @return bool False if directory cannot be created, true otherwise.
+	 * @param string     $path  Path for new directory.
+	 * @param int|false  $chmod Optional. The permissions as octal number (or false to skip chmod).
+	 *                          Default false.
+	 * @param string|int $chown Optional. A user name or number (or false to skip chown).
+	 *                          Default false.
+	 * @param string|int $chgrp Optional. A group name or number (or false to skip chgrp).
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
 		return false;
 	}
 
 	/**
-	 * Delete a directory.
+	 * Deletes a directory.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -780,14 +788,14 @@ class WP_Filesystem_Base {
 	 * @param string $path      Path to directory.
 	 * @param bool   $recursive Optional. Whether to recursively remove files/directories.
 	 *                          Default false.
-	 * @return bool Whether directory is deleted successfully or not.
+	 * @return bool True on success, false on failure.
 	 */
 	public function rmdir( $path, $recursive = false ) {
 		return false;
 	}
 
 	/**
-	 * Get details for files in a directory or a specific file.
+	 * Gets details for files in a directory or a specific file.
 	 *
 	 * @since 2.5.0
 	 * @abstract
@@ -797,10 +805,10 @@ class WP_Filesystem_Base {
 	 *                               Default true.
 	 * @param bool   $recursive      Optional. Whether to recursively include file details in nested directories.
 	 *                               Default false.
-	 * @return array|bool {
+	 * @return array|false {
 	 *     Array of files. False if unable to list directory contents.
 	 *
-	 *     @type string $name        Name of the file/directory.
+	 *     @type string $name        Name of the file or directory.
 	 *     @type string $perms       *nix representation of permissions.
 	 *     @type int    $permsn      Octal representation of permissions.
 	 *     @type string $owner       Owner name or ID.
diff --git a/src/wp-admin/includes/class-wp-filesystem-direct.php b/src/wp-admin/includes/class-wp-filesystem-direct.php
index f7d6cb159f..41839097f0 100644
--- a/src/wp-admin/includes/class-wp-filesystem-direct.php
+++ b/src/wp-admin/includes/class-wp-filesystem-direct.php
@@ -16,9 +16,11 @@
 class WP_Filesystem_Direct extends WP_Filesystem_Base {
 
 	/**
-	 * constructor
+	 * Constructor.
 	 *
-	 * @param mixed $arg ignored argument
+	 * @since 2.5.0
+	 *
+	 * @param mixed $arg Not used.
 	 */
 	public function __construct( $arg ) {
 		$this->method = 'direct';
@@ -26,33 +28,39 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Reads entire file into a string
+	 * Reads entire file into a string.
+	 *
+	 * @since 2.5.0
 	 *
 	 * @param string $file Name of the file to read.
-	 * @return string|bool The function returns the read data or false on failure.
+	 * @return string|false Read data on success, false on failure.
 	 */
 	public function get_contents( $file ) {
 		return @file_get_contents( $file );
 	}
 
 	/**
-	 * Reads entire file into an array
+	 * Reads entire file into an array.
+	 *
+	 * @since 2.5.0
 	 *
 	 * @param string $file Path to the file.
-	 * @return array|bool the file contents in an array or false on failure.
+	 * @return array|false File contents in an array on success, false on failure.
 	 */
 	public function get_contents_array( $file ) {
 		return @file( $file );
 	}
 
 	/**
-	 * Write a string to a file
+	 * Writes a string to a file.
 	 *
-	 * @param string $file     Remote path to the file where to write the data.
-	 * @param string $contents The data to write.
-	 * @param int    $mode     Optional. The file permissions as octal number, usually 0644.
-	 *                         Default false.
-	 * @return bool False upon failure, true otherwise.
+	 * @since 2.5.0
+	 *
+	 * @param string    $file     Remote path to the file where to write the data.
+	 * @param string    $contents The data to write.
+	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function put_contents( $file, $contents, $mode = false ) {
 		$fp = @fopen( $file, 'wb' );
@@ -80,31 +88,38 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Gets the current working directory
+	 * Gets the current working directory.
 	 *
-	 * @return string|bool the current working directory on success, or false on failure.
+	 * @since 2.5.0
+	 *
+	 * @return string|false The current working directory on success, false on failure.
 	 */
 	public function cwd() {
 		return @getcwd();
 	}
 
 	/**
-	 * Change directory
+	 * Changes current directory.
+	 *
+	 * @since 2.5.0
 	 *
 	 * @param string $dir The new current directory.
-	 * @return bool Returns true on success or false on failure.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chdir( $dir ) {
 		return @chdir( $dir );
 	}
 
 	/**
-	 * Changes file group
+	 * Changes the file group.
 	 *
-	 * @param string $file      Path to the file.
-	 * @param mixed  $group     A group name or number.
-	 * @param bool   $recursive Optional. If set True changes file group recursively. Default false.
-	 * @return bool Returns true on success or false on failure.
+	 * @since 2.5.0
+	 *
+	 * @param string     $file      Path to the file.
+	 * @param string|int $group     A group name or number.
+	 * @param bool       $recursive Optional. If set to true, changes file group recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chgrp( $file, $group, $recursive = false ) {
 		if ( ! $this->exists( $file ) ) {
@@ -127,13 +142,16 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Changes filesystem permissions
+	 * Changes filesystem permissions.
 	 *
-	 * @param string $file      Path to the file.
-	 * @param int    $mode      Optional. The permissions as octal number, usually 0644 for files,
-	 *                          0755 for dirs. Default false.
-	 * @param bool   $recursive Optional. If set True changes file group recursively. Default false.
-	 * @return bool Returns true on success or false on failure.
+	 * @since 2.5.0
+	 *
+	 * @param string    $file      Path to the file.
+	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,
+	 *                             0755 for directories. Default false.
+	 * @param bool      $recursive Optional. If set to true, changes file group recursively.
+	 *                             Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chmod( $file, $mode = false, $recursive = false ) {
 		if ( ! $mode ) {
@@ -160,13 +178,15 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Changes file owner
+	 * Changes the owner of a file or directory.
 	 *
-	 * @param string $file      Path to the file.
-	 * @param mixed  $owner     A user name or number.
-	 * @param bool   $recursive Optional. If set True changes file owner recursively.
-	 *                          Default false.
-	 * @return bool Returns true on success or false on failure.
+	 * @since 2.5.0
+	 *
+	 * @param string     $file      Path to the file or directory.
+	 * @param string|int $owner     A user name or number.
+	 * @param bool       $recursive Optional. If set to true, changes file owner recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chown( $file, $owner, $recursive = false ) {
 		if ( ! $this->exists( $file ) ) {
@@ -187,10 +207,12 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Gets file owner
+	 * Gets the file owner.
+	 *
+	 * @since 2.5.0
 	 *
 	 * @param string $file Path to the file.
-	 * @return string|bool Username of the user or false on error.
+	 * @return string|false Username of the owner on success, false on failure.
 	 */
 	public function owner( $file ) {
 		$owneruid = @fileowner( $file );
@@ -205,20 +227,26 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Gets file permissions
+	 * Gets the permissions of the specified file or filepath in their octal format.
 	 *
 	 * FIXME does not handle errors in fileperms()
 	 *
+	 * @since 2.5.0
+	 *
 	 * @param string $file Path to the file.
-	 * @return string Mode of the file (last 3 digits).
+	 * @return string Mode of the file (the last 3 digits).
 	 */
 	public function getchmod( $file ) {
 		return substr( decoct( @fileperms( $file ) ), -3 );
 	}
 
 	/**
-	 * @param string $file
-	 * @return string|false
+	 * Gets the file's group.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false The group on success, false on failure.
 	 */
 	public function group( $file ) {
 		$gid = @filegroup( $file );
@@ -233,11 +261,17 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool   $overwrite
-	 * @param int    $mode
-	 * @return bool
+	 * Copies a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $source      Path to the source file.
+	 * @param string    $destination Path to the destination file.
+	 * @param bool      $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                               Default false.
+	 * @param int|false $mode        Optional. The permissions as octal number, usually 0644 for files,
+	 *                               0755 for dirs. Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
 		if ( ! $overwrite && $this->exists( $destination ) ) {
@@ -252,10 +286,15 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool $overwrite
-	 * @return bool
+	 * Moves a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $source      Path to the source file.
+	 * @param string $destination Path to the destination file.
+	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function move( $source, $destination, $overwrite = false ) {
 		if ( ! $overwrite && $this->exists( $destination ) ) {
@@ -276,10 +315,16 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @param bool $recursive
-	 * @param string $type
-	 * @return bool
+	 * Deletes a file or directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string       $file      Path to the file or directory.
+	 * @param bool         $recursive Optional. If set to true, changes file group recursively.
+	 *                                Default false.
+	 * @param string|false $type      Type of resource. 'f' for file, 'd' for directory.
+	 *                                Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function delete( $file, $recursive = false, $type = false ) {
 		if ( empty( $file ) ) { // Some filesystems report this as /, which can cause non-expected recursive deletion of all files in the filesystem.
@@ -313,73 +358,116 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 
 		return $retval;
 	}
+
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory exists.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file exists or not.
 	 */
 	public function exists( $file ) {
 		return @file_exists( $file );
 	}
+
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if resource is a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file File path.
+	 * @return bool Whether $file is a file.
 	 */
 	public function is_file( $file ) {
 		return @is_file( $file );
 	}
+
 	/**
-	 * @param string $path
-	 * @return bool
+	 * Checks if resource is a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path Directory path.
+	 * @return bool Whether $path is a directory.
 	 */
 	public function is_dir( $path ) {
 		return @is_dir( $path );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file is readable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return bool Whether $file is readable.
 	 */
 	public function is_readable( $file ) {
 		return @is_readable( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory is writable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file is writable.
 	 */
 	public function is_writable( $file ) {
 		return @is_writable( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file's last access time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing last access time, false on failure.
 	 */
 	public function atime( $file ) {
 		return @fileatime( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file modification time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing modification time, false on failure.
 	 */
 	public function mtime( $file ) {
 		return @filemtime( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file size (in bytes).
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Size of the file in bytes on success, false on failure.
 	 */
 	public function size( $file ) {
 		return @filesize( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @param int $time
-	 * @param int $atime
-	 * @return bool
+	 * Sets the access and modification times of a file.
+	 *
+	 * Note: If $file doesn't exist, it will be created.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file  Path to file.
+	 * @param int    $time  Optional. Modified time to set for file.
+	 *                      Default 0.
+	 * @param int    $atime Optional. Access time to set for file.
+	 *                      Default 0.
+	 * @return bool True on success, false on failure.
 	 */
 	public function touch( $file, $time = 0, $atime = 0 ) {
 		if ( $time == 0 ) {
@@ -392,11 +480,18 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param mixed  $chmod
-	 * @param mixed  $chown
-	 * @param mixed  $chgrp
-	 * @return bool
+	 * Creates a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string     $path  Path for new directory.
+	 * @param int|false  $chmod Optional. The permissions as octal number (or false to skip chmod).
+	 *                          Default false.
+	 * @param string|int $chown Optional. A user name or number (or false to skip chown).
+	 *                          Default false.
+	 * @param string|int $chgrp Optional. A group name or number (or false to skip chgrp).
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
 		// Safe mode fails with a trailing slash under certain PHP versions.
@@ -423,19 +518,43 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool $recursive
-	 * @return bool
+	 * Deletes a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path      Path to directory.
+	 * @param bool   $recursive Optional. Whether to recursively remove files/directories.
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function rmdir( $path, $recursive = false ) {
 		return $this->delete( $path, $recursive );
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool $include_hidden
-	 * @param bool $recursive
-	 * @return bool|array
+	 * Gets details for files in a directory or a specific file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path           Path to directory or file.
+	 * @param bool   $include_hidden Optional. Whether to include details of hidden ("." prefixed) files.
+	 *                               Default true.
+	 * @param bool   $recursive      Optional. Whether to recursively include file details in nested directories.
+	 *                               Default false.
+	 * @return array|false {
+	 *     Array of files. False if unable to list directory contents.
+	 *
+	 *     @type string $name        Name of the file or directory.
+	 *     @type string $perms       *nix representation of permissions.
+	 *     @type int    $permsn      Octal representation of permissions.
+	 *     @type string $owner       Owner name or ID.
+	 *     @type int    $size        Size of file in bytes.
+	 *     @type int    $lastmodunix Last modified unix timestamp.
+	 *     @type mixed  $lastmod     Last modified month (3 letter) and day (without leading 0).
+	 *     @type int    $time        Last modified time.
+	 *     @type string $type        Type of resource. 'f' for file, 'd' for directory.
+	 *     @type mixed  $files       If a directory and $recursive is true, contains another array of files.
+	 * }
 	 */
 	public function dirlist( $path, $include_hidden = true, $recursive = false ) {
 		if ( $this->is_file( $path ) ) {
diff --git a/src/wp-admin/includes/class-wp-filesystem-ftpext.php b/src/wp-admin/includes/class-wp-filesystem-ftpext.php
index 36648e1844..1db0a57917 100644
--- a/src/wp-admin/includes/class-wp-filesystem-ftpext.php
+++ b/src/wp-admin/includes/class-wp-filesystem-ftpext.php
@@ -14,9 +14,18 @@
  * @see WP_Filesystem_Base
  */
 class WP_Filesystem_FTPext extends WP_Filesystem_Base {
+
+	/**
+	 * @since 2.5.0
+	 * @var resource
+	 */
 	public $link;
 
 	/**
+	 * Constructor.
+	 *
+	 * @since 2.5.0
+	 *
 	 * @param array $opt
 	 */
 	public function __construct( $opt = '' ) {
@@ -67,7 +76,11 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return bool
+	 * Connects filesystem.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @return bool True on success, false on failure.
 	 */
 	public function connect() {
 		if ( isset( $this->options['ssl'] ) && $this->options['ssl'] && function_exists( 'ftp_ssl_connect' ) ) {
@@ -110,12 +123,12 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Retrieves the file contents.
+	 * Reads entire file into a string.
 	 *
 	 * @since 2.5.0
 	 *
-	 * @param string $file Filename.
-	 * @return string|false File contents on success, false if no temp file could be opened,
+	 * @param string $file Name of the file to read.
+	 * @return string|false Read data on success, false if no temporary file could be opened,
 	 *                      or if the file couldn't be retrieved.
 	 */
 	public function get_contents( $file ) {
@@ -137,7 +150,7 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		$contents = '';
 
 		while ( ! feof( $temp ) ) {
-			$contents .= fread( $temp, 8192 );
+			$contents .= fread( $temp, 8 * KB_IN_BYTES );
 		}
 
 		fclose( $temp );
@@ -146,18 +159,27 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return array
+	 * Reads entire file into an array.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return array|false File contents in an array on success, false on failure.
 	 */
 	public function get_contents_array( $file ) {
 		return explode( "\n", $this->get_contents( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @param string $contents
-	 * @param bool|int $mode
-	 * @return bool
+	 * Writes a string to a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $file     Remote path to the file where to write the data.
+	 * @param string    $contents The data to write.
+	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function put_contents( $file, $contents, $mode = false ) {
 		$tempfile = wp_tempnam( $file );
@@ -194,7 +216,11 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return string
+	 * Gets the current working directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @return string|false The current working directory on success, false on failure.
 	 */
 	public function cwd() {
 		$cwd = @ftp_pwd( $this->link );
@@ -205,18 +231,28 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $dir
-	 * @return bool
+	 * Changes current directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $dir The new current directory.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chdir( $dir ) {
 		return @ftp_chdir( $this->link, $dir );
 	}
 
 	/**
-	 * @param string $file
-	 * @param int $mode
-	 * @param bool $recursive
-	 * @return bool
+	 * Changes filesystem permissions.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $file      Path to the file.
+	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,
+	 *                             0755 for directories. Default false.
+	 * @param bool      $recursive Optional. If set to true, changes file group recursively.
+	 *                             Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chmod( $file, $mode = false, $recursive = false ) {
 		if ( ! $mode ) {
@@ -245,16 +281,25 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the file owner.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false Username of the owner on success, false on failure.
 	 */
 	public function owner( $file ) {
 		$dir = $this->dirlist( $file );
 		return $dir[ $file ]['owner'];
 	}
+
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the permissions of the specified file or filepath in their octal format.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string Mode of the file (the last 3 digits).
 	 */
 	public function getchmod( $file ) {
 		$dir = $this->dirlist( $file );
@@ -262,8 +307,12 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the file's group.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false The group on success, false on failure.
 	 */
 	public function group( $file ) {
 		$dir = $this->dirlist( $file );
@@ -271,11 +320,17 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool   $overwrite
-	 * @param string|bool $mode
-	 * @return bool
+	 * Copies a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $source      Path to the source file.
+	 * @param string    $destination Path to the destination file.
+	 * @param bool      $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                               Default false.
+	 * @param int|false $mode        Optional. The permissions as octal number, usually 0644 for files,
+	 *                               0755 for dirs. Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
 		if ( ! $overwrite && $this->exists( $destination ) ) {
@@ -289,20 +344,31 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool $overwrite
-	 * @return bool
+	 * Moves a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $source      Path to the source file.
+	 * @param string $destination Path to the destination file.
+	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function move( $source, $destination, $overwrite = false ) {
 		return ftp_rename( $this->link, $source, $destination );
 	}
 
 	/**
-	 * @param string $file
-	 * @param bool $recursive
-	 * @param string $type
-	 * @return bool
+	 * Deletes a file or directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string       $file      Path to the file or directory.
+	 * @param bool         $recursive Optional. If set to true, changes file group recursively.
+	 *                                Default false.
+	 * @param string|false $type      Type of resource. 'f' for file, 'd' for directory.
+	 *                                Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function delete( $file, $recursive = false, $type = false ) {
 		if ( empty( $file ) ) {
@@ -325,8 +391,12 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory exists.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file exists or not.
 	 */
 	public function exists( $file ) {
 		$list = @ftp_nlist( $this->link, $file );
@@ -339,16 +409,24 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if resource is a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file File path.
+	 * @return bool Whether $file is a file.
 	 */
 	public function is_file( $file ) {
 		return $this->exists( $file ) && ! $this->is_dir( $file );
 	}
 
 	/**
-	 * @param string $path
-	 * @return bool
+	 * Checks if resource is a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path Directory path.
+	 * @return bool Whether $path is a directory.
 	 */
 	public function is_dir( $path ) {
 		$cwd    = $this->cwd();
@@ -361,59 +439,96 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file is readable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return bool Whether $file is readable.
 	 */
 	public function is_readable( $file ) {
 		return true;
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory is writable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file is writable.
 	 */
 	public function is_writable( $file ) {
 		return true;
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Gets the file's last access time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing last access time, false on failure.
 	 */
 	public function atime( $file ) {
 		return false;
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file modification time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing modification time, false on failure.
 	 */
 	public function mtime( $file ) {
 		return ftp_mdtm( $this->link, $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file size (in bytes).
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Size of the file in bytes on success, false on failure.
 	 */
 	public function size( $file ) {
 		return ftp_size( $this->link, $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Sets the access and modification times of a file.
+	 *
+	 * Note: If $file doesn't exist, it will be created.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file  Path to file.
+	 * @param int    $time  Optional. Modified time to set for file.
+	 *                      Default 0.
+	 * @param int    $atime Optional. Access time to set for file.
+	 *                      Default 0.
+	 * @return bool True on success, false on failure.
 	 */
 	public function touch( $file, $time = 0, $atime = 0 ) {
 		return false;
 	}
 
 	/**
-	 * @param string $path
-	 * @param mixed $chmod
-	 * @param mixed $chown
-	 * @param mixed $chgrp
-	 * @return bool
+	 * Creates a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string     $path  Path for new directory.
+	 * @param int|false  $chmod Optional. The permissions as octal number (or false to skip chmod).
+	 *                          Default false.
+	 * @param string|int $chown Optional. A user name or number (or false to skip chown).
+	 *                          Default false.
+	 * @param string|int $chgrp Optional. A group name or number (or false to skip chgrp).
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
 		$path = untrailingslashit( $path );
@@ -429,9 +544,14 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool $recursive
-	 * @return bool
+	 * Deletes a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path      Path to directory.
+	 * @param bool   $recursive Optional. Whether to recursively remove files/directories.
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function rmdir( $path, $recursive = false ) {
 		return $this->delete( $path, $recursive );
@@ -523,10 +643,29 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool $include_hidden
-	 * @param bool $recursive
-	 * @return bool|array
+	 * Gets details for files in a directory or a specific file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path           Path to directory or file.
+	 * @param bool   $include_hidden Optional. Whether to include details of hidden ("." prefixed) files.
+	 *                               Default true.
+	 * @param bool   $recursive      Optional. Whether to recursively include file details in nested directories.
+	 *                               Default false.
+	 * @return array|false {
+	 *     Array of files. False if unable to list directory contents.
+	 *
+	 *     @type string $name        Name of the file or directory.
+	 *     @type string $perms       *nix representation of permissions.
+	 *     @type int    $permsn      Octal representation of permissions.
+	 *     @type string $owner       Owner name or ID.
+	 *     @type int    $size        Size of file in bytes.
+	 *     @type int    $lastmodunix Last modified unix timestamp.
+	 *     @type mixed  $lastmod     Last modified month (3 letter) and day (without leading 0).
+	 *     @type int    $time        Last modified time.
+	 *     @type string $type        Type of resource. 'f' for file, 'd' for directory.
+	 *     @type mixed  $files       If a directory and $recursive is true, contains another array of files.
+	 * }
 	 */
 	public function dirlist( $path = '.', $include_hidden = true, $recursive = false ) {
 		if ( $this->is_file( $path ) ) {
@@ -537,13 +676,13 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		}
 
 		$pwd = @ftp_pwd( $this->link );
-		if ( ! @ftp_chdir( $this->link, $path ) ) { // Cant change to folder = folder doesn't exist
+		if ( ! @ftp_chdir( $this->link, $path ) ) { // Can't change to folder = folder doesn't exist.
 			return false;
 		}
 		$list = @ftp_rawlist( $this->link, '-a', false );
 		@ftp_chdir( $this->link, $pwd );
 
-		if ( empty( $list ) ) { // Empty array = non-existent folder (real folder will show . at least)
+		if ( empty( $list ) ) { // Empty array = non-existent folder (real folder will show . at least).
 			return false;
 		}
 
@@ -585,6 +724,9 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	/**
+	 * Destructor.
+	 *
+	 * @since 2.5.0
 	 */
 	public function __destruct() {
 		if ( $this->link ) {
diff --git a/src/wp-admin/includes/class-wp-filesystem-ftpsockets.php b/src/wp-admin/includes/class-wp-filesystem-ftpsockets.php
index 45f1235ce6..77a7a66875 100644
--- a/src/wp-admin/includes/class-wp-filesystem-ftpsockets.php
+++ b/src/wp-admin/includes/class-wp-filesystem-ftpsockets.php
@@ -14,12 +14,18 @@
  * @see WP_Filesystem_Base
  */
 class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
+
 	/**
+	 * @since 2.5.0
 	 * @var ftp
 	 */
 	public $ftp;
 
 	/**
+	 * Constructor.
+	 *
+	 * @since 2.5.0
+	 *
 	 * @param array $opt
 	 */
 	public function __construct( $opt = '' ) {
@@ -59,7 +65,11 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return bool
+	 * Connects filesystem.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @return bool True on success, false on failure.
 	 */
 	public function connect() {
 		if ( ! $this->ftp ) {
@@ -111,13 +121,13 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Retrieves the file contents.
+	 * Reads entire file into a string.
 	 *
 	 * @since 2.5.0
 	 *
-	 * @param string $file Filename.
-	 * @return string|false File contents on success, false if no temp file could be opened,
-	 *                      or if the file doesn't exist.
+	 * @param string $file Name of the file to read.
+	 * @return string|false Read data on success, false if no temporary file could be opened,
+	 *                      or if the file couldn't be retrieved.
 	 */
 	public function get_contents( $file ) {
 		if ( ! $this->exists( $file ) ) {
@@ -148,7 +158,7 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 		$contents = '';
 
 		while ( ! feof( $temphandle ) ) {
-			$contents .= fread( $temphandle, 8192 );
+			$contents .= fread( $temphandle, 8 * KB_IN_BYTES );
 		}
 
 		fclose( $temphandle );
@@ -157,18 +167,27 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return array
+	 * Reads entire file into an array.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return array|false File contents in an array on success, false on failure.
 	 */
 	public function get_contents_array( $file ) {
 		return explode( "\n", $this->get_contents( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @param string $contents
-	 * @param int|bool $mode
-	 * @return bool
+	 * Writes a string to a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $file     Remote path to the file where to write the data.
+	 * @param string    $contents The data to write.
+	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function put_contents( $file, $contents, $mode = false ) {
 		$temp = wp_tempnam( $file );
@@ -205,7 +224,11 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return string
+	 * Gets the current working directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @return string|false The current working directory on success, false on failure.
 	 */
 	public function cwd() {
 		$cwd = $this->ftp->pwd();
@@ -216,18 +239,28 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Changes current directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $dir The new current directory.
+	 * @return bool True on success, false on failure.
 	 */
-	public function chdir( $file ) {
-		return $this->ftp->chdir( $file );
+	public function chdir( $dir ) {
+		return $this->ftp->chdir( $dir );
 	}
 
 	/**
-	 * @param string $file
-	 * @param int|bool $mode
-	 * @param bool $recursive
-	 * @return bool
+	 * Changes filesystem permissions.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $file      Path to the file.
+	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,
+	 *                             0755 for directories. Default false.
+	 * @param bool      $recursive Optional. If set to true, changes file group recursively.
+	 *                             Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chmod( $file, $mode = false, $recursive = false ) {
 		if ( ! $mode ) {
@@ -253,8 +286,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the file owner.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false Username of the owner on success, false on failure.
 	 */
 	public function owner( $file ) {
 		$dir = $this->dirlist( $file );
@@ -262,8 +299,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the permissions of the specified file or filepath in their octal format.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string Mode of the file (the last 3 digits).
 	 */
 	public function getchmod( $file ) {
 		$dir = $this->dirlist( $file );
@@ -271,8 +312,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the file's group.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false The group on success, false on failure.
 	 */
 	public function group( $file ) {
 		$dir = $this->dirlist( $file );
@@ -280,11 +325,17 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string   $source
-	 * @param string   $destination
-	 * @param bool     $overwrite
-	 * @param int|bool $mode
-	 * @return bool
+	 * Copies a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string    $source      Path to the source file.
+	 * @param string    $destination Path to the destination file.
+	 * @param bool      $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                               Default false.
+	 * @param int|false $mode        Optional. The permissions as octal number, usually 0644 for files,
+	 *                               0755 for dirs. Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
 		if ( ! $overwrite && $this->exists( $destination ) ) {
@@ -300,20 +351,31 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool   $overwrite
-	 * @return bool
+	 * Moves a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $source      Path to the source file.
+	 * @param string $destination Path to the destination file.
+	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function move( $source, $destination, $overwrite = false ) {
 		return $this->ftp->rename( $source, $destination );
 	}
 
 	/**
-	 * @param string $file
-	 * @param bool   $recursive
-	 * @param string $type
-	 * @return bool
+	 * Deletes a file or directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string       $file      Path to the file or directory.
+	 * @param bool         $recursive Optional. If set to true, changes file group recursively.
+	 *                                Default false.
+	 * @param string|false $type      Type of resource. 'f' for file, 'd' for directory.
+	 *                                Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function delete( $file, $recursive = false, $type = false ) {
 		if ( empty( $file ) ) {
@@ -330,8 +392,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory exists.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file exists or not.
 	 */
 	public function exists( $file ) {
 		$list = $this->ftp->nlist( $file );
@@ -345,8 +411,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if resource is a file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file File path.
+	 * @return bool Whether $file is a file.
 	 */
 	public function is_file( $file ) {
 		if ( $this->is_dir( $file ) ) {
@@ -359,8 +429,12 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @return bool
+	 * Checks if resource is a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path Directory path.
+	 * @return bool Whether $path is a directory.
 	 */
 	public function is_dir( $path ) {
 		$cwd = $this->cwd();
@@ -372,61 +446,96 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file is readable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return bool Whether $file is readable.
 	 */
 	public function is_readable( $file ) {
 		return true;
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory is writable.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file is writable.
 	 */
 	public function is_writable( $file ) {
 		return true;
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Gets the file's last access time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing last access time, false on failure.
 	 */
 	public function atime( $file ) {
 		return false;
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file modification time.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing modification time, false on failure.
 	 */
 	public function mtime( $file ) {
 		return $this->ftp->mdtm( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file size (in bytes).
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Size of the file in bytes on success, false on failure.
 	 */
 	public function size( $file ) {
 		return $this->ftp->filesize( $file );
 	}
 
 	/**
-	 * @param string $file
-	 * @param int $time
-	 * @param int $atime
-	 * @return bool
+	 * Sets the access and modification times of a file.
+	 *
+	 * Note: If $file doesn't exist, it will be created.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $file  Path to file.
+	 * @param int    $time  Optional. Modified time to set for file.
+	 *                      Default 0.
+	 * @param int    $atime Optional. Access time to set for file.
+	 *                      Default 0.
+	 * @return bool True on success, false on failure.
 	 */
 	public function touch( $file, $time = 0, $atime = 0 ) {
 		return false;
 	}
 
 	/**
-	 * @param string $path
-	 * @param mixed  $chmod
-	 * @param mixed  $chown
-	 * @param mixed  $chgrp
-	 * @return bool
+	 * Creates a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string     $path  Path for new directory.
+	 * @param int|false  $chmod Optional. The permissions as octal number (or false to skip chmod).
+	 *                          Default false.
+	 * @param string|int $chown Optional. A user name or number (or false to skip chown).
+	 *                          Default false.
+	 * @param string|int $chgrp Optional. A group name or number (or false to skip chgrp).
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
 		$path = untrailingslashit( $path );
@@ -445,19 +554,43 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool $recursive
-	 * @return bool
+	 * Deletes a directory.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path      Path to directory.
+	 * @param bool   $recursive Optional. Whether to recursively remove files/directories.
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function rmdir( $path, $recursive = false ) {
 		return $this->delete( $path, $recursive );
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool   $include_hidden
-	 * @param bool   $recursive
-	 * @return bool|array
+	 * Gets details for files in a directory or a specific file.
+	 *
+	 * @since 2.5.0
+	 *
+	 * @param string $path           Path to directory or file.
+	 * @param bool   $include_hidden Optional. Whether to include details of hidden ("." prefixed) files.
+	 *                               Default true.
+	 * @param bool   $recursive      Optional. Whether to recursively include file details in nested directories.
+	 *                               Default false.
+	 * @return array|false {
+	 *     Array of files. False if unable to list directory contents.
+	 *
+	 *     @type string $name        Name of the file or directory.
+	 *     @type string $perms       *nix representation of permissions.
+	 *     @type int    $permsn      Octal representation of permissions.
+	 *     @type string $owner       Owner name or ID.
+	 *     @type int    $size        Size of file in bytes.
+	 *     @type int    $lastmodunix Last modified unix timestamp.
+	 *     @type mixed  $lastmod     Last modified month (3 letter) and day (without leading 0).
+	 *     @type int    $time        Last modified time.
+	 *     @type string $type        Type of resource. 'f' for file, 'd' for directory.
+	 *     @type mixed  $files       If a directory and $recursive is true, contains another array of files.
+	 * }
 	 */
 	public function dirlist( $path = '.', $include_hidden = true, $recursive = false ) {
 		if ( $this->is_file( $path ) ) {
@@ -517,6 +650,9 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	/**
+	 * Destructor.
+	 *
+	 * @since 2.5.0
 	 */
 	public function __destruct() {
 		$this->ftp->quit();
diff --git a/src/wp-admin/includes/class-wp-filesystem-ssh2.php b/src/wp-admin/includes/class-wp-filesystem-ssh2.php
index 82101beacd..b87a195724 100644
--- a/src/wp-admin/includes/class-wp-filesystem-ssh2.php
+++ b/src/wp-admin/includes/class-wp-filesystem-ssh2.php
@@ -36,16 +36,28 @@
 class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 
 	/**
+	 * @since 2.7.0
+	 * @var resource
 	 */
 	public $link = false;
 
 	/**
+	 * @since 2.7.0
 	 * @var resource
 	 */
 	public $sftp_link;
+
+	/**
+	 * @since 2.7.0
+	 * @var bool
+	 */
 	public $keys = false;
 
 	/**
+	 * Constructor.
+	 *
+	 * @since 2.7.0
+	 *
 	 * @param array $opt
 	 */
 	public function __construct( $opt = '' ) {
@@ -109,7 +121,11 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return bool
+	 * Connects filesystem.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @return bool True on success, false on failure.
 	 */
 	public function connect() {
 		if ( ! $this->keys ) {
@@ -193,6 +209,8 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
+	 * @since 2.7.0
+	 *
 	 * @param string $command
 	 * @param bool $returnbool
 	 * @return bool|string True on success, false on failure. String if the command was executed, `$returnbool`
@@ -228,26 +246,40 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string|false
+	 * Reads entire file into a string.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Name of the file to read.
+	 * @return string|false Read data on success, false if no temporary file could be opened,
+	 *                      or if the file couldn't be retrieved.
 	 */
 	public function get_contents( $file ) {
 		return file_get_contents( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return array
+	 * Reads entire file into an array.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return array|false File contents in an array on success, false on failure.
 	 */
 	public function get_contents_array( $file ) {
 		return file( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string   $file
-	 * @param string   $contents
-	 * @param bool|int $mode
-	 * @return bool
+	 * Writes a string to a file.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string    $file     Remote path to the file where to write the data.
+	 * @param string    $contents The data to write.
+	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function put_contents( $file, $contents, $mode = false ) {
 		$ret = file_put_contents( $this->sftp_path( $file ), $contents );
@@ -262,7 +294,11 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @return bool
+	 * Gets the current working directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @return string|false The current working directory on success, false on failure.
 	 */
 	public function cwd() {
 		$cwd = ssh2_sftp_realpath( $this->sftp_link, '.' );
@@ -273,19 +309,27 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $dir
-	 * @return bool|string
+	 * Changes current directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $dir The new current directory.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chdir( $dir ) {
 		return $this->run_command( 'cd ' . $dir, true );
 	}
 
 	/**
-	 * @param string $file
-	 * @param string $group
-	 * @param bool   $recursive
+	 * Changes the file group.
 	 *
-	 * @return bool
+	 * @since 2.7.0
+	 *
+	 * @param string     $file      Path to the file.
+	 * @param string|int $group     A group name or number.
+	 * @param bool       $recursive Optional. If set to true, changes file group recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chgrp( $file, $group, $recursive = false ) {
 		if ( ! $this->exists( $file ) ) {
@@ -298,10 +342,16 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @param int    $mode
-	 * @param bool   $recursive
-	 * @return bool|string
+	 * Changes filesystem permissions.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string    $file      Path to the file.
+	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,
+	 *                             0755 for directories. Default false.
+	 * @param bool      $recursive Optional. If set to true, changes file group recursively.
+	 *                             Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chmod( $file, $mode = false, $recursive = false ) {
 		if ( ! $this->exists( $file ) ) {
@@ -325,12 +375,15 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * Change the ownership of a file / folder.
+	 * Changes the owner of a file or directory.
 	 *
-	 * @param string     $file      Path to the file.
+	 * @since 2.7.0
+	 *
+	 * @param string     $file      Path to the file or directory.
 	 * @param string|int $owner     A user name or number.
-	 * @param bool       $recursive Optional. If set True changes file owner recursivly. Default False.
-	 * @return bool True on success or false on failure.
+	 * @param bool       $recursive Optional. If set to true, changes file owner recursively.
+	 *                              Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function chown( $file, $owner, $recursive = false ) {
 		if ( ! $this->exists( $file ) ) {
@@ -343,8 +396,12 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string|false
+	 * Gets the file owner.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false Username of the owner on success, false on failure.
 	 */
 	public function owner( $file ) {
 		$owneruid = @fileowner( $this->sftp_path( $file ) );
@@ -359,16 +416,24 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return string
+	 * Gets the permissions of the specified file or filepath in their octal format.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string Mode of the file (the last 3 digits).
 	 */
 	public function getchmod( $file ) {
 		return substr( decoct( @fileperms( $this->sftp_path( $file ) ) ), -3 );
 	}
 
 	/**
-	 * @param string $file
-	 * @return string|false
+	 * Gets the file's group.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to the file.
+	 * @return string|false The group on success, false on failure.
 	 */
 	public function group( $file ) {
 		$gid = @filegroup( $this->sftp_path( $file ) );
@@ -383,11 +448,17 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string   $source
-	 * @param string   $destination
-	 * @param bool     $overwrite
-	 * @param int|bool $mode
-	 * @return bool
+	 * Copies a file.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string    $source      Path to the source file.
+	 * @param string    $destination Path to the destination file.
+	 * @param bool      $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                               Default false.
+	 * @param int|false $mode        Optional. The permissions as octal number, usually 0644 for files,
+	 *                               0755 for dirs. Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function copy( $source, $destination, $overwrite = false, $mode = false ) {
 		if ( ! $overwrite && $this->exists( $destination ) ) {
@@ -401,20 +472,31 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $source
-	 * @param string $destination
-	 * @param bool   $overwrite
-	 * @return bool
+	 * Moves a file.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $source      Path to the source file.
+	 * @param string $destination Path to the destination file.
+	 * @param bool   $overwrite   Optional. Whether to overwrite the destination file if it exists.
+	 *                            Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function move( $source, $destination, $overwrite = false ) {
 		return @ssh2_sftp_rename( $this->sftp_link, $source, $destination );
 	}
 
 	/**
-	 * @param string      $file
-	 * @param bool        $recursive
-	 * @param string|bool $type
-	 * @return bool
+	 * Deletes a file or directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string       $file      Path to the file or directory.
+	 * @param bool         $recursive Optional. If set to true, changes file group recursively.
+	 *                                Default false.
+	 * @param string|false $type      Type of resource. 'f' for file, 'd' for directory.
+	 *                                Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function delete( $file, $recursive = false, $type = false ) {
 		if ( 'f' == $type || $this->is_file( $file ) ) {
@@ -433,40 +515,60 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory exists.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file exists or not.
 	 */
 	public function exists( $file ) {
 		return file_exists( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if resource is a file.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file File path.
+	 * @return bool Whether $file is a file.
 	 */
 	public function is_file( $file ) {
 		return is_file( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $path
-	 * @return bool
+	 * Checks if resource is a directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $path Directory path.
+	 * @return bool Whether $path is a directory.
 	 */
 	public function is_dir( $path ) {
 		return is_dir( $this->sftp_path( $path ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file is readable.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file.
+	 * @return bool Whether $file is readable.
 	 */
 	public function is_readable( $file ) {
 		return is_readable( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return bool
+	 * Checks if a file or directory is writable.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file or directory.
+	 * @return bool Whether $file is writable.
 	 */
 	public function is_writable( $file ) {
 		// PHP will base it's writable checks on system_user === file_owner, not ssh_user === file_owner
@@ -474,44 +576,71 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file's last access time.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing last access time, false on failure.
 	 */
 	public function atime( $file ) {
 		return fileatime( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file modification time.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Unix timestamp representing modification time, false on failure.
 	 */
 	public function mtime( $file ) {
 		return filemtime( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @return int
+	 * Gets the file size (in bytes).
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file Path to file.
+	 * @return int|false Size of the file in bytes on success, false on failure.
 	 */
 	public function size( $file ) {
 		return filesize( $this->sftp_path( $file ) );
 	}
 
 	/**
-	 * @param string $file
-	 * @param int    $time
-	 * @param int    $atime
+	 * Sets the access and modification times of a file.
+	 *
+	 * Note: Not implemented.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $file  Path to file.
+	 * @param int    $time  Optional. Modified time to set for file.
+	 *                      Default 0.
+	 * @param int    $atime Optional. Access time to set for file.
+	 *                      Default 0.
 	 */
 	public function touch( $file, $time = 0, $atime = 0 ) {
-		//Not implemented.
+		// Not implemented.
 	}
 
 	/**
-	 * @param string $path
-	 * @param mixed  $chmod
-	 * @param mixed  $chown
-	 * @param mixed  $chgrp
-	 * @return bool
+	 * Creates a directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string     $path  Path for new directory.
+	 * @param int|false  $chmod Optional. The permissions as octal number (or false to skip chmod).
+	 *                          Default false.
+	 * @param string|int $chown Optional. A user name or number (or false to skip chown).
+	 *                          Default false.
+	 * @param string|int $chgrp Optional. A group name or number (or false to skip chgrp).
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function mkdir( $path, $chmod = false, $chown = false, $chgrp = false ) {
 		$path = untrailingslashit( $path );
@@ -535,19 +664,43 @@ class WP_Filesystem_SSH2 extends WP_Filesystem_Base {
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool   $recursive
-	 * @return bool
+	 * Deletes a directory.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $path      Path to directory.
+	 * @param bool   $recursive Optional. Whether to recursively remove files/directories.
+	 *                          Default false.
+	 * @return bool True on success, false on failure.
 	 */
 	public function rmdir( $path, $recursive = false ) {
 		return $this->delete( $path, $recursive );
 	}
 
 	/**
-	 * @param string $path
-	 * @param bool   $include_hidden
-	 * @param bool   $recursive
-	 * @return bool|array
+	 * Gets details for files in a directory or a specific file.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param string $path           Path to directory or file.
+	 * @param bool   $include_hidden Optional. Whether to include details of hidden ("." prefixed) files.
+	 *                               Default true.
+	 * @param bool   $recursive      Optional. Whether to recursively include file details in nested directories.
+	 *                               Default false.
+	 * @return array|false {
+	 *     Array of files. False if unable to list directory contents.
+	 *
+	 *     @type string $name        Name of the file or directory.
+	 *     @type string $perms       *nix representation of permissions.
+	 *     @type int    $permsn      Octal representation of permissions.
+	 *     @type string $owner       Owner name or ID.
+	 *     @type int    $size        Size of file in bytes.
+	 *     @type int    $lastmodunix Last modified unix timestamp.
+	 *     @type mixed  $lastmod     Last modified month (3 letter) and day (without leading 0).
+	 *     @type int    $time        Last modified time.
+	 *     @type string $type        Type of resource. 'f' for file, 'd' for directory.
+	 *     @type mixed  $files       If a directory and $recursive is true, contains another array of files.
+	 * }
 	 */
 	public function dirlist( $path, $include_hidden = true, $recursive = false ) {
 		if ( $this->is_file( $path ) ) {