chore: Adds docstring for LlmAgent.disallow_transfer_to_parent to clarify the expected behavior.

PiperOrigin-RevId: 758676926

src/google/adk/agents/llm_agent.py

@@ -16,15 +16,13 @@ from __future__ import annotations
 
 import inspect
 import logging
-from typing import (
+from typing import Any
-    Any,
+from typing import AsyncGenerator
-    AsyncGenerator,
+from typing import Awaitable
-    Awaitable,
+from typing import Callable
-    Callable,
+from typing import Literal
-    Literal,
+from typing import Optional
-    Optional,
+from typing import Union
-    Union,
-)
 
 from google.genai import types
 from pydantic import BaseModel
@@ -152,7 +150,12 @@ class LlmAgent(BaseAgent):
 
   # LLM-based agent transfer configs - Start
   disallow_transfer_to_parent: bool = False
-  """Disallows LLM-controlled transferring to the parent agent."""
+  """Disallows LLM-controlled transferring to the parent agent.
+
+  NOTE: Setting this as True also prevents this agent to continue reply to the
+  end-user. This behavior prevents one-way transfer, in which end-user may be
+  stuck with one agent that cannot transfer to other agents in the agent tree.
+  """
   disallow_transfer_to_peers: bool = False
   """Disallows LLM-controlled transferring to the peer agents."""
   # LLM-based agent transfer configs - End