[Bugfix] Fix tool parsing crash with non-function tool types (e.g. WebSearchTool) (#45147)

Signed-off-by: Ben Browning <bbrownin@redhat.com>

tests/tool_use/test_tool_choice_required.py

@@ -5,13 +5,17 @@ from copy import deepcopy
 
 import pytest
 import regex as re
+from openai.types.responses import FunctionTool, WebSearchTool
 from pydantic import TypeAdapter
 
 from vllm.entrypoints.openai.chat_completion.protocol import (
     ChatCompletionToolsParam,
 )
 from vllm.tool_parsers.streaming import extract_required_tool_call_streaming
-from vllm.tool_parsers.utils import get_json_schema_from_tools
+from vllm.tool_parsers.utils import (
+    find_tool_properties,
+    get_json_schema_from_tools,
+)
 
 pytestmark = pytest.mark.cpu_test
 
@@ -354,3 +358,37 @@ def test_streaming_output_valid_with_trailing_extra_data():
         previous_text = current_text
 
     assert len(messages) > 0
+
+
+FUNCTION_TOOL = FunctionTool(
+    type="function",
+    name="get_weather",
+    parameters={
+        "type": "object",
+        "properties": {"city": {"type": "string"}},
+        "required": ["city"],
+    },
+)
+WEB_SEARCH_TOOL = WebSearchTool(type="web_search")
+
+
+class TestNonFunctionToolsSkipped:
+    """Non-function tools (web_search, etc.) must be silently skipped
+    by the tool-schema utilities instead of raising TypeError."""
+
+    def test_find_tool_properties_skips_web_search(self):
+        tools = [WEB_SEARCH_TOOL, FUNCTION_TOOL]
+        props = find_tool_properties(tools, "get_weather")
+        assert props == {"city": {"type": "string"}}
+
+    def test_find_tool_properties_only_non_function_tools(self):
+        props = find_tool_properties([WEB_SEARCH_TOOL], "get_weather")
+        assert props == {}
+
+    def test_get_json_schema_with_mixed_tools(self):
+        tools = [WEB_SEARCH_TOOL, FUNCTION_TOOL]
+        schema = get_json_schema_from_tools(tools=tools, tool_choice="required")
+        assert isinstance(schema, dict)
+        any_of = schema["items"]["anyOf"]
+        assert len(any_of) == 1
+        assert any_of[0]["properties"]["name"]["enum"] == ["get_weather"]

vllm/tool_parsers/utils.py

@@ -151,6 +151,10 @@ def consume_space(i: int, s: str) -> int:
     return i
 
 
+def _is_function_tool(tool: Tool) -> bool:
+    return isinstance(tool, (FunctionTool, ChatCompletionToolsParam))
+
+
 def _extract_tool_info(
     tool: Tool,
 ) -> tuple[str, dict[str, Any] | None]:
@@ -170,6 +174,8 @@ def find_tool_properties(
     if not tools:
         return {}
     for tool in tools:
+        if not _is_function_tool(tool):
+            continue
         name, params = _extract_tool_info(tool)
         if name == tool_name:
             return (params or {}).get("properties", {})
@@ -210,15 +216,16 @@ def _get_tool_schema_defs(
 def _get_json_schema_from_tools(
     tools: list[Tool],
 ) -> dict:
+    fn_tools = [t for t in tools if _is_function_tool(t)]
     json_schema = {
         "type": "array",
         "minItems": 1,
         "items": {
             "type": "object",
-            "anyOf": [_get_tool_schema_from_tool(tool) for tool in tools],
+            "anyOf": [_get_tool_schema_from_tool(tool) for tool in fn_tools],
         },
     }
-    json_schema_defs = _get_tool_schema_defs(tools)
+    json_schema_defs = _get_tool_schema_defs(fn_tools)
     if json_schema_defs:
         json_schema["$defs"] = json_schema_defs
     return json_schema