Python: Respect FunctionChoiceBehavior filters in OpenAI responses agent tools (#13235)

issue: #13234

## Summary
- honor FunctionChoiceBehavior filters when retrieving kernel function
metadata
 
### Contribution Checklist

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

---------

Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>

Author: ymuichiro

python/semantic_kernel/agents/open_ai/responses_agent_thread_actions.py

@@ -1214,10 +1214,19 @@ def _get_tools(
         if agent.tools:
             tools.extend(agent.tools)
 
-        # TODO(evmattso): make sure to respect filters on FCB
-        if kernel.plugins:
-            funcs = kernel.get_full_list_of_function_metadata()
-            tools.extend([kernel_function_metadata_to_response_function_call_format(f) for f in funcs])
+        if not function_choice_behavior.enable_kernel_functions:
+            return tools
+
+        if not kernel.plugins:
+            return tools
+
+        funcs = (
+            kernel.get_list_of_function_metadata(function_choice_behavior.filters)
+            if function_choice_behavior.filters
+            else kernel.get_full_list_of_function_metadata()
+        )
+
+        tools.extend([kernel_function_metadata_to_response_function_call_format(f) for f in funcs])
 
         return tools
 

python/tests/unit/agents/openai_responses/test_openai_responses_thread_actions.py

@@ -15,6 +15,7 @@
 
 from semantic_kernel.agents.open_ai.openai_responses_agent import OpenAIResponsesAgent
 from semantic_kernel.agents.open_ai.responses_agent_thread_actions import ResponsesAgentThreadActions
+from semantic_kernel.connectors.ai.function_choice_behavior import FunctionChoiceBehavior
 from semantic_kernel.contents.chat_message_content import ChatMessageContent
 from semantic_kernel.contents.streaming_chat_message_content import StreamingChatMessageContent
 from semantic_kernel.contents.streaming_text_content import StreamingTextContent
@@ -499,11 +500,11 @@ async def mock_invoke_function_call(*args, **kwargs):
 
 def test_get_tools(mock_agent, kernel, custom_plugin_class):
     kernel.add_plugin(custom_plugin_class)
-
+    fcb = FunctionChoiceBehavior()
     tools = ResponsesAgentThreadActions._get_tools(
         agent=mock_agent,
         kernel=kernel,
-        function_choice_behavior=MagicMock(),
+        function_choice_behavior=fcb,
     )
 
     assert len(tools) == len(mock_agent.tools) + len(kernel.get_full_list_of_function_metadata())