feat: GenAI Client(evals): Add warning message when tool usage is empty for tool_use_quality

tests/unit/vertexai/genai/test_evals.py

@@ -1515,6 +1515,64 @@ def test_run_inference_with_litellm_parsing(
         pd.testing.assert_frame_equal(call_kwargs["prompt_dataset"], mock_df)
 
 
+@pytest.mark.usefixtures("google_auth_mock")
+class TestEvalsMetricHandlers:
+    """Unit tests for utility functions in _evals_metric_handlers."""
+
+    def test_has_tool_call_with_tool_call(self):
+        events = [
+            vertexai_genai_types.evals.Event(
+                event_id="1",
+                content=genai_types.Content(
+                    parts=[
+                        genai_types.Part(
+                            function_call=genai_types.FunctionCall(
+                                name="search", args={}
+                            )
+                        )
+                    ]
+                ),
+            )
+        ]
+        assert _evals_metric_handlers._has_tool_call(events)
+
+    def test_has_tool_call_no_tool_call(self):
+        events = [
+            vertexai_genai_types.evals.Event(
+                event_id="1",
+                content=genai_types.Content(parts=[genai_types.Part(text="hello")]),
+            )
+        ]
+        assert not _evals_metric_handlers._has_tool_call(events)
+
+    def test_has_tool_call_empty_events(self):
+        assert not _evals_metric_handlers._has_tool_call([])
+
+    def test_has_tool_call_none_events(self):
+        assert not _evals_metric_handlers._has_tool_call(None)
+
+    def test_has_tool_call_mixed_events(self):
+        events = [
+            vertexai_genai_types.evals.Event(
+                event_id="1",
+                content=genai_types.Content(parts=[genai_types.Part(text="hello")]),
+            ),
+            vertexai_genai_types.evals.Event(
+                event_id="2",
+                content=genai_types.Content(
+                    parts=[
+                        genai_types.Part(
+                            function_call=genai_types.FunctionCall(
+                                name="search", args={}
+                            )
+                        )
+                    ]
+                ),
+            ),
+        ]
+        assert _evals_metric_handlers._has_tool_call(events)
+
+
 @pytest.mark.usefixtures("google_auth_mock")
 class TestRunAgentInternal:
     """Unit tests for the _run_agent_internal function."""
@@ -3890,6 +3948,39 @@ def test_eval_case_to_agent_data_agent_info_empty(self):
 
         assert agent_data.agent_config is None
 
+    @mock.patch.object(_evals_metric_handlers.logger, "warning")
+    def test_tool_use_quality_metric_no_tool_call_logs_warning(
+        self, mock_warning, mock_api_client_fixture
+    ):
+        """Tests that PredefinedMetricHandler warns for tool_use_quality_v1 if no tool call."""
+        metric = vertexai_genai_types.Metric(name="tool_use_quality_v1")
+        handler = _evals_metric_handlers.PredefinedMetricHandler(
+            module=evals.Evals(api_client_=mock_api_client_fixture), metric=metric
+        )
+        eval_case = vertexai_genai_types.EvalCase(
+            eval_case_id="case-no-tool-call",
+            prompt=genai_types.Content(parts=[genai_types.Part(text="Hello")]),
+            responses=[
+                vertexai_genai_types.ResponseCandidate(
+                    response=genai_types.Content(parts=[genai_types.Part(text="Hi")])
+                )
+            ],
+            intermediate_events=[
+                vertexai_genai_types.evals.Event(
+                    event_id="event1",
+                    content=genai_types.Content(
+                        parts=[genai_types.Part(text="intermediate event")]
+                    ),
+                )
+            ],
+        )
+        handler._build_request_payload(eval_case, response_index=0)
+        mock_warning.assert_called_once_with(
+            "Metric 'tool_use_quality_v1' requires tool usage in "
+            "'intermediate_events', but no tool usage was found for case %s.",
+            "case-no-tool-call",
+        )
+
 
 @pytest.mark.usefixtures("google_auth_mock")
 class TestLLMMetricHandlerPayload:

vertexai/_genai/_evals_metric_handlers.py

@@ -39,6 +39,18 @@
 _MAX_RETRIES = 3
 
 
+def _has_tool_call(intermediate_events: Optional[list[types.evals.Event]]) -> bool:
+    """Checks if any event in intermediate_events has a function call."""
+    if not intermediate_events:
+        return False
+    for event in intermediate_events:
+        if event.content and event.content.parts:
+            for part in event.content.parts:
+                if hasattr(part, "function_call") and part.function_call:
+                    return True
+    return False
+
+
 def _extract_text_from_content(
     content: Optional[genai_types.Content], warn_property: str = "text"
 ) -> Optional[str]:
@@ -903,6 +915,14 @@ def _build_request_payload(
                 f"Response content missing for candidate {response_index}."
             )
 
+        if self.metric.name == "tool_use_quality_v1":
+            if not _has_tool_call(eval_case.intermediate_events):
+                logger.warning(
+                    "Metric 'tool_use_quality_v1' requires tool usage in "
+                    "'intermediate_events', but no tool usage was found for case %s.",
+                    eval_case.eval_case_id,
+                )
+
         reference_instance_data = None
         if eval_case.reference:
             reference_instance_data = PredefinedMetricHandler._content_to_instance_data(