diff --git a/src/wp-content/themes/twentynineteen/inc/template-functions.php b/src/wp-content/themes/twentynineteen/inc/template-functions.php
index aa4e62cd64..301ac23116 100644
--- a/src/wp-content/themes/twentynineteen/inc/template-functions.php
+++ b/src/wp-content/themes/twentynineteen/inc/template-functions.php
@@ -96,12 +96,13 @@ function twentynineteen_get_the_archive_title() {
 add_filter( 'get_the_archive_title', 'twentynineteen_get_the_archive_title' );
 
 /**
- * Add custom sizes attribute to responsive image functionality for post thumbnails.
+ * Add custom 'sizes' attribute to responsive image functionality for post thumbnails.
  *
  * @origin Twenty Nineteen 1.0
  *
- * @param array $attr  Attributes for the image markup.
- * @return string Value for use in post thumbnail 'sizes' attribute.
+ * @param string[] $attr Array of attribute values for the image markup, keyed by attribute name.
+ *                       See wp_get_attachment_image().
+ * @return string[] The filtered attributes for the image markup.
  */
 function twentynineteen_post_thumbnail_sizes_attr( $attr ) {
 
diff --git a/src/wp-content/themes/twentyseventeen/functions.php b/src/wp-content/themes/twentyseventeen/functions.php
index c99a8c9a91..3e0ddc9991 100644
--- a/src/wp-content/themes/twentyseventeen/functions.php
+++ b/src/wp-content/themes/twentyseventeen/functions.php
@@ -573,10 +573,12 @@ add_filter( 'get_header_image_tag', 'twentyseventeen_header_image_tag', 10, 3 );
  *
  * @since Twenty Seventeen 1.0
  *
- * @param array $attr       Attributes for the image markup.
- * @param int   $attachment Image attachment ID.
- * @param array $size       Registered image size or flat array of height and width dimensions.
- * @return array The filtered attributes for the image markup.
+ * @param string[]     $attr       Array of attribute values for the image markup, keyed by attribute name.
+ *                                 See wp_get_attachment_image().
+ * @param WP_Post      $attachment Image attachment post.
+ * @param string|int[] $size       Requested image size. Can be any registered image size name, or
+ *                                 an array of width and height values in pixels (in that order).
+ * @return string[] The filtered attributes for the image markup.
  */
 function twentyseventeen_post_thumbnail_sizes_attr( $attr, $attachment, $size ) {
 	if ( is_archive() || is_search() || is_home() ) {
diff --git a/src/wp-content/themes/twentysixteen/functions.php b/src/wp-content/themes/twentysixteen/functions.php
index b5b7c207a9..a6207071c5 100644
--- a/src/wp-content/themes/twentysixteen/functions.php
+++ b/src/wp-content/themes/twentysixteen/functions.php
@@ -559,10 +559,12 @@ add_filter( 'wp_calculate_image_sizes', 'twentysixteen_content_image_sizes_attr'
  *
  * @since Twenty Sixteen 1.0
  *
- * @param array $attr Attributes for the image markup.
- * @param int   $attachment Image attachment ID.
- * @param array $size Registered image size or flat array of height and width dimensions.
- * @return array The filtered attributes for the image markup.
+ * @param string[]     $attr       Array of attribute values for the image markup, keyed by attribute name.
+ *                                 See wp_get_attachment_image().
+ * @param WP_Post      $attachment Image attachment post.
+ * @param string|int[] $size       Requested image size. Can be any registered image size name, or
+ *                                 an array of width and height values in pixels (in that order).
+ * @return string[] The filtered attributes for the image markup.
  */
 function twentysixteen_post_thumbnail_sizes_attr( $attr, $attachment, $size ) {
 	if ( 'post-thumbnail' === $size ) {
diff --git a/src/wp-content/themes/twentytwentyone/inc/template-functions.php b/src/wp-content/themes/twentytwentyone/inc/template-functions.php
index 1e61ba3054..839a77a368 100644
--- a/src/wp-content/themes/twentytwentyone/inc/template-functions.php
+++ b/src/wp-content/themes/twentytwentyone/inc/template-functions.php
@@ -432,12 +432,12 @@ add_filter( 'the_password_form', 'twenty_twenty_one_password_form', 10, 2 );
  *
  * @since Twenty Twenty-One 1.0
  *
- * @param array        $attr       Array of attribute values for the image markup, keyed by attribute name.
+ * @param string[]     $attr       Array of attribute values for the image markup, keyed by attribute name.
  *                                 See wp_get_attachment_image().
  * @param WP_Post      $attachment Image attachment post.
- * @param string|array $size       Requested size. Image size or array of width and height values
- *                                 (in that order). Default 'thumbnail'.
- * @return array
+ * @param string|int[] $size       Requested image size. Can be any registered image size name, or
+ *                                 an array of width and height values in pixels (in that order).
+ * @return string[] The filtered attributes for the image markup.
  */
 function twenty_twenty_one_get_attachment_image_attributes( $attr, $attachment, $size ) {