diff --git a/src/claude_agent_sdk/client.py b/src/claude_agent_sdk/client.py
index 742d7d64..47fbf821 100644
--- a/src/claude_agent_sdk/client.py
+++ b/src/claude_agent_sdk/client.py
@@ -220,6 +220,7 @@ async def set_permission_mode(self, mode: str) -> None:
             mode: The permission mode to set. Valid options:
                 - 'default': CLI prompts for dangerous tools
                 - 'acceptEdits': Auto-accept file edits
+                - 'plan': Claude must get user approval before making changes
                 - 'bypassPermissions': Allow all tools (use with caution)
 
         Example: