diff -u b/core/modules/comment/js/comment-new-indicator.js b/core/modules/comment/js/comment-new-indicator.js
--- b/core/modules/comment/js/comment-new-indicator.js
+++ b/core/modules/comment/js/comment-new-indicator.js
@@ -14,6 +14,9 @@
    * Renders "new" comment indicators wherever necessary.
    *
    * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches "new" comment indicators behavior.
    */
   Drupal.behaviors.commentNewIndicator = {
     attach: function (context) {
diff -u b/core/modules/comment/js/node-new-comments-link.js b/core/modules/comment/js/node-new-comments-link.js
--- b/core/modules/comment/js/node-new-comments-link.js
+++ b/core/modules/comment/js/node-new-comments-link.js
@@ -14,6 +14,9 @@
    * Render "X new comments" links wherever necessary.
    *
    * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches new comment links behavior.
    */
   Drupal.behaviors.nodeNewCommentsLink = {
     attach: function (context) {
@@ -143,7 +146,7 @@
      * retrieve the same data.
      *
      * @param {object} results
-     *   The server response for new comment links.
+     *   Data about new comment links indexed by nodeID.
      */
     function render(results) {
       for (var nodeID in results) {