fix: disable AFC when there are AFC incompatible tool presented.

PiperOrigin-RevId: 812201451

Author: wanlin31

google/genai/_extra_utils.py

@@ -115,6 +115,33 @@ def format_destination(
   return config
 
 
+def find_afc_incompatible_tool_indexes(
+    config: Optional[types.GenerateContentConfigOrDict] = None,
+) -> list[int]:
+  """Checks if the config contains any AFC incompatible tools.
+
+  A `types.Tool` object that contains `function_declarations` is considered a
+  non-AFC tool for this execution path.
+
+  Returns:
+    True if any tool is a `types.Tool` with function declarations,
+    False otherwise.
+  """
+  if not config:
+    return []
+  config_model = _create_generate_content_config_model(config)
+  incompatible_tools_indexes: list[int] = []
+
+  if not config_model or not config_model.tools:
+    return incompatible_tools_indexes
+
+  for index, tool in enumerate(config_model.tools):
+    if isinstance(tool, types.Tool) and tool.function_declarations:
+      incompatible_tools_indexes.append(index)
+
+  return incompatible_tools_indexes
+
+
 def get_function_map(
     config: Optional[types.GenerateContentConfigOrDict] = None,
     mcp_to_genai_tool_adapters: Optional[

google/genai/models.py

@@ -6439,6 +6439,9 @@ def generate_content(
       # scones.
     """
 
+    incompatible_tools_indexes = (
+        _extra_utils.find_afc_incompatible_tool_indexes(config)
+    )
     parsed_config = _extra_utils.parse_config_for_mcp_usage(config)
     if (
         parsed_config
@@ -6452,6 +6455,26 @@ def generate_content(
       return self._generate_content(
           model=model, contents=contents, config=parsed_config
       )
+    if incompatible_tools_indexes:
+      original_tools_length = 0
+      if isinstance(config, types.GenerateContentConfig):
+        if config.tools:
+          original_tools_length = len(config.tools)
+      elif isinstance(config, dict):
+        tools = config.get('tools', [])
+        if tools:
+          original_tools_length = len(tools)
+      if len(incompatible_tools_indexes) != original_tools_length:
+        indices_str = ', '.join(map(str, incompatible_tools_indexes))
+        logger.warning(
+            'Tools at indices [%s] are not compatible with automatic function '
+            'calling. AFC will be disabled.',
+            indices_str,
+        )
+      return self._generate_content(
+          model=model, contents=contents, config=parsed_config
+      )
+
     remaining_remote_calls_afc = _extra_utils.get_max_remote_calls_afc(
         parsed_config
     )
@@ -6575,6 +6598,9 @@ def generate_content_stream(
       # scones.
     """
 
+    incompatible_tools_indexes = (
+        _extra_utils.find_afc_incompatible_tool_indexes(config)
+    )
     parsed_config = _extra_utils.parse_config_for_mcp_usage(config)
     if (
         parsed_config
@@ -6590,6 +6616,27 @@ def generate_content_stream(
       )
       return
 
+    if incompatible_tools_indexes:
+      original_tools_length = 0
+      if isinstance(config, types.GenerateContentConfig):
+        if config.tools:
+          original_tools_length = len(config.tools)
+      elif isinstance(config, dict):
+        tools = config.get('tools', [])
+        if tools:
+          original_tools_length = len(tools)
+      if len(incompatible_tools_indexes) != original_tools_length:
+        indices_str = ', '.join(map(str, incompatible_tools_indexes))
+        logger.warning(
+            'Tools at indices [%s] are not compatible with automatic function '
+            'calling. AFC will be disabled.',
+            indices_str,
+        )
+      yield from self._generate_content_stream(
+          model=model, contents=contents, config=parsed_config
+      )
+      return
+
     remaining_remote_calls_afc = _extra_utils.get_max_remote_calls_afc(
         parsed_config
     )
@@ -8172,13 +8219,35 @@ async def generate_content(
       # J'aime les bagels.
     """
     # Retrieve and cache any MCP sessions if provided.
+    incompatible_tools_indexes = (
+        _extra_utils.find_afc_incompatible_tool_indexes(config)
+    )
     parsed_config, mcp_to_genai_tool_adapters = (
         await _extra_utils.parse_config_for_mcp_sessions(config)
     )
     if _extra_utils.should_disable_afc(parsed_config):
       return await self._generate_content(
           model=model, contents=contents, config=parsed_config
       )
+    if incompatible_tools_indexes:
+      original_tools_length = 0
+      if isinstance(config, types.GenerateContentConfig):
+        if config.tools:
+          original_tools_length = len(config.tools)
+      elif isinstance(config, dict):
+        tools = config.get('tools', [])
+        if tools:
+          original_tools_length = len(tools)
+      if len(incompatible_tools_indexes) != original_tools_length:
+        indices_str = ', '.join(map(str, incompatible_tools_indexes))
+        logger.warning(
+            'Tools at indices [%s] are not compatible with automatic function '
+            'calling. AFC will be disabled.',
+            indices_str,
+        )
+      return await self._generate_content(
+          model=model, contents=contents, config=parsed_config
+      )
     remaining_remote_calls_afc = _extra_utils.get_max_remote_calls_afc(
         parsed_config
     )
@@ -8303,6 +8372,10 @@ async def generate_content_stream(
       # scones.
     """
 
+    # Retrieve and cache any MCP sessions if provided.
+    incompatible_tools_indexes = (
+        _extra_utils.find_afc_incompatible_tool_indexes(config)
+    )
     # Retrieve and cache any MCP sessions if provided.
     parsed_config, mcp_to_genai_tool_adapters = (
         await _extra_utils.parse_config_for_mcp_sessions(config)
@@ -8318,6 +8391,32 @@ async def base_async_generator(model, contents, config):  # type: ignore[no-unty
 
       return base_async_generator(model, contents, parsed_config)  # type: ignore[no-untyped-call, no-any-return]
 
+    if incompatible_tools_indexes:
+      original_tools_length = 0
+      if isinstance(config, types.GenerateContentConfig):
+        if config.tools:
+          original_tools_length = len(config.tools)
+      elif isinstance(config, dict):
+        tools = config.get('tools', [])
+        if tools:
+          original_tools_length = len(tools)
+      if len(incompatible_tools_indexes) != original_tools_length:
+        indices_str = ', '.join(map(str, incompatible_tools_indexes))
+        logger.warning(
+            'Tools at indices [%s] are not compatible with automatic function '
+            'calling. AFC will be disabled.',
+            indices_str,
+        )
+      response = await self._generate_content_stream(
+          model=model, contents=contents, config=parsed_config
+      )
+
+      async def base_async_generator(model, contents, config):  # type: ignore[no-untyped-def]
+        async for chunk in response:  # type: ignore[attr-defined]
+          yield chunk
+
+      return base_async_generator(model, contents, parsed_config)  # type: ignore[no-untyped-call, no-any-return]
+
     async def async_generator(model, contents, config):  # type: ignore[no-untyped-def]
       remaining_remote_calls_afc = _extra_utils.get_max_remote_calls_afc(config)
       logger.info(