diff --git a/packages/core/src/metadata/di.ts b/packages/core/src/metadata/di.ts
index 0d4abd05d9..f3fc53925b 100644
--- a/packages/core/src/metadata/di.ts
+++ b/packages/core/src/metadata/di.ts
@@ -132,6 +132,9 @@ export interface ContentChildrenDecorator {
    *
    * Content queries are set before the `ngAfterContentInit` callback is called.
    *
+   * Does not retrieve elements or directives that are in other components' templates,
+   * since a component's template is always a black box to its ancestors.
+   *
    * **Metadata Properties**:
    *
    * * **selector** - The directive type or the name used for querying.
@@ -194,6 +197,9 @@ export interface ContentChildDecorator {
    *
    * Content queries are set before the `ngAfterContentInit` callback is called.
    *
+   * Does not retrieve elements or directives that are in other components' templates,
+   * since a component's template is always a black box to its ancestors.
+   *
    * **Metadata Properties**:
    *
    * * **selector** - The directive type or the name used for querying.