diff --git a/packages/block-library/src/gallery/use-get-media.js b/packages/block-library/src/gallery/use-get-media.js
index 1bf33c767a4c64..2d70119e4aa229 100644
--- a/packages/block-library/src/gallery/use-get-media.js
+++ b/packages/block-library/src/gallery/use-get-media.js
@@ -5,6 +5,14 @@ import { useState } from '@wordpress/element';
 import { useSelect } from '@wordpress/data';
 import { store as coreStore } from '@wordpress/core-data';
 
+/**
+ * Retrieves the extended media info for each gallery image from the store. This is used to
+ * determine which image size options are available for the current gallery.
+ *
+ * @param {Array} innerBlockImages An array of the innerBlock images currently in the gallery.
+ *
+ * @return {Array} An array of media info options for each gallery image.
+ */
 export default function useGetMedia( innerBlockImages ) {
 	const [ currentImageMedia, setCurrentImageMedia ] = useState( [] );
 
diff --git a/packages/block-library/src/gallery/use-get-new-images.js b/packages/block-library/src/gallery/use-get-new-images.js
index 67578a5cb9941b..056cf1d2ff6ba1 100644
--- a/packages/block-library/src/gallery/use-get-new-images.js
+++ b/packages/block-library/src/gallery/use-get-new-images.js
@@ -3,6 +3,16 @@
  */
 import { useMemo, useState } from '@wordpress/element';
 
+/**
+ * Keeps track of images already in the gallery to allow new innerBlocks to be identified. This
+ * is required so default gallery attributes can be applied without overwriting any custom
+ * attributes applied to existing images.
+ *
+ * @param {Array} images    Basic image block data taken from current gallery innerBlock
+ * @param {Array} imageData The related image data for each of the current gallery images.
+ *
+ * @return {Array} An array of any new images that have been added to the gallery.
+ */
 export default function useGetNewImages( images, imageData ) {
 	const [ currentImages, setCurrentImages ] = useState( [] );
 
diff --git a/packages/block-library/src/gallery/use-image-sizes.js b/packages/block-library/src/gallery/use-image-sizes.js
index 5b406adab4cc9a..877bacb67dd137 100644
--- a/packages/block-library/src/gallery/use-image-sizes.js
+++ b/packages/block-library/src/gallery/use-image-sizes.js
@@ -8,6 +8,16 @@ import { get, some } from 'lodash';
  */
 import { useMemo } from '@wordpress/element';
 
+/**
+ * Calculates the image sizes that are avaible for the current gallery images in order to
+ * populate the 'Image size' selector.
+ *
+ * @param {Array}    images      Basic image block data taken from current gallery innerBlock
+ * @param {boolean}  isSelected  Is the block currently selected in the editor.
+ * @param {Function} getSettings Block editor store selector.
+ *
+ * @return {Array} An array of image size options.
+ */
 export default function useImageSizes( images, isSelected, getSettings ) {
 	return useMemo( () => getImageSizing(), [ images, isSelected ] );
 
diff --git a/packages/block-library/src/gallery/use-short-code-transform.js b/packages/block-library/src/gallery/use-short-code-transform.js
index 3843df9d5a6427..bc251119104083 100644
--- a/packages/block-library/src/gallery/use-short-code-transform.js
+++ b/packages/block-library/src/gallery/use-short-code-transform.js
@@ -9,6 +9,14 @@ import { every } from 'lodash';
 import { useSelect } from '@wordpress/data';
 import { store as coreStore } from '@wordpress/core-data';
 
+/**
+ * Shortcode transforms don't currently have a tranform method and so can't use a selector to
+ * retrieve the data for each image being transformer, so this selector handle this post transformation.
+ *
+ * @param {Array} shortCodeTransforms An array of image data passed from the shortcode transform.
+ *
+ * @return {Array} An array of extended image data objects for each of the shortcode transform images.
+ */
 export default function useShortCodeTransform( shortCodeTransforms ) {
 	const newImageData = useSelect(
 		( select ) => {