docs: update output_schema docstring to reflect support for tools and output_schema together

PiperOrigin-RevId: 907857917

Author: google-genai-bot

src/google/adk/agents/llm_agent.py

@@ -339,8 +339,9 @@ class LlmAgent(BaseAgent):
     - Schema: Google's Schema type
 
   NOTE:
-    When this is set, agent can ONLY reply and CANNOT use any tools, such as
-    function tools, RAGs, agent transfer, etc.
+    The ADK supports using `output_schema` and `tools` together. It works by
+    exposing tools during the thought loop and enforcing structure only on the
+    final output.
   """
   output_key: Optional[str] = None
   """The key in session state to store the output of the agent.