diff --git a/packages/core/src/interface/lifecycle_hooks.ts b/packages/core/src/interface/lifecycle_hooks.ts
index e73a8791cde17..2807d10c36a4a 100644
--- a/packages/core/src/interface/lifecycle_hooks.ts
+++ b/packages/core/src/interface/lifecycle_hooks.ts
@@ -127,7 +127,7 @@ export interface OnDestroy {
 /**
  * @description
  * A lifecycle hook that is called after Angular has fully initialized
- * all content of a directive.
+ * all content of a directive. It will run only once when the projected content is initialized.
  * Define an `ngAfterContentInit()` method to handle any additional initialization tasks.
  *
  * @see `OnInit`
@@ -155,7 +155,8 @@ export interface AfterContentInit {
 /**
  * @description
  * A lifecycle hook that is called after the default change detector has
- * completed checking all content of a directive.
+ * completed checking all content of a directive. It will run after the content
+ * has been checked and most of the time it's during a change detection cycle.
  *
  * @see `AfterViewChecked`
  * @see [Lifecycle hooks guide](guide/lifecycle-hooks)