diff --git a/core/lib/Drupal/Core/Config/ConfigEvents.php b/core/lib/Drupal/Core/Config/ConfigEvents.php
index 794fbc5..c60fe5f 100644
--- a/core/lib/Drupal/Core/Config/ConfigEvents.php
+++ b/core/lib/Drupal/Core/Config/ConfigEvents.php
@@ -10,6 +10,13 @@
 /**
  * Defines events for the configuration system.
  *
+ * Subscribers for these events can not make any assumption that the config data
+ * is valid and should limit their actions to:
+ *  - cache invalidation
+ *  - enforcing related config change
+ *  - marking a container for rebuild
+ * For other changes, higher-level entity hooks should be used instead.
+ *
  * @see \Drupal\Core\Config\ConfigCrudEvent
  */
 final class ConfigEvents {