diff --git wp-includes/customize/class-wp-customize-selective-refresh.php wp-includes/customize/class-wp-customize-selective-refresh.php
index 23d5a9488..39a6954e0 100644
--- wp-includes/customize/class-wp-customize-selective-refresh.php
+++ wp-includes/customize/class-wp-customize-selective-refresh.php
@@ -91,7 +91,28 @@ final class WP_Customize_Selective_Refresh {
 	 * @access public
 	 *
 	 * @param WP_Customize_Partial|string $id   Customize Partial object, or Panel ID.
-	 * @param array                       $args Optional. Partial arguments. Default empty array.
+	 * @param array                       $args {
+	 *     Optional. Array of properties for the new Partials object. Default empty array.
+	 *
+	 *     @type string   $type                  Type of the partial to be created.
+	 *     @type string   $selector              The jQuery selector to find the container element for the partial.
+	 *     @type array    $settings              IDs for settings tied to the partial.
+	 *     @type string   $primary_setting       The ID for the setting that this partial is primarily responsible for
+	 *                                           rendering. If not supplied, it will default to the ID of the first setting.
+	 *     @type string   $capability            Capability required to edit this partial.
+	 *                                           Normally this is empty and the capability is derived from the capabilities
+	 *                                           of the associated `$settings`.
+	 *     @type callable $render_callback       Render callback.
+	 *                                           Callback is called with one argument, the instance of WP_Customize_Partial.
+	 *                                           The callback can either echo the partial or return the partial as a string,
+	 *                                           or return false if error.
+	 *     @type bool     $container_inclusive   Whether the container element is included in the partial, or if only
+	 *                                           the contents are rendered.
+	 *     @type bool     $fallback_refresh      Whether to refresh the entire preview in case a partial cannot be refreshed.
+	 *                                           A partial render is considered a failure if the render_callback returns
+	 *                                           false.
+	 * }
+	 *
 	 * @return WP_Customize_Partial             The instance of the panel that was added.
 	 */
 	public function add_partial( $id, $args = array() ) {