feat(telemetry): add tool type attribute to tool execution duration

Add `gen_ai.tool.type` attribute to tool execution duration metric, as suggested in the OTel semconv update PR: open-telemetry/semantic-conventions-genai#201.

PiperOrigin-RevId: 938566496

Author: google-genai-bot

src/google/adk/telemetry/_instrumentation.py

@@ -175,6 +175,7 @@ async def record_tool_execution(
     try:
       _metrics.record_tool_execution_duration(
           tool_name=tool.name,
+          tool_type=tool.__class__.__name__,
           agent_name=agent.name,
           elapsed_s=_get_elapsed_s(span, start_time),
           error=caught_error,

src/google/adk/telemetry/_metrics.py

@@ -191,6 +191,7 @@ def record_agent_workflow_steps(agent_name: str, events: list[Event]):
 
 def record_tool_execution_duration(
     tool_name: str,
+    tool_type: str,
     agent_name: str,
     elapsed_s: float,
     error: Exception | None = None,
@@ -199,6 +200,7 @@ def record_tool_execution_duration(
   attrs = {
       gen_ai_attributes.GEN_AI_AGENT_NAME: agent_name,
       gen_ai_attributes.GEN_AI_TOOL_NAME: tool_name,
+      gen_ai_attributes.GEN_AI_TOOL_TYPE: tool_type,
   }
   if error is not None:
     attrs[error_attributes.ERROR_TYPE] = type(error).__name__

tests/unittests/telemetry/test_functional.py

@@ -299,13 +299,15 @@ async def generate_random_number():
           attributes={
               "gen_ai.agent.name": "complex_agent",
               "gen_ai.tool.name": "generate_random_number",
+              "gen_ai.tool.type": "FunctionTool",
           },
           value=None,
       ),
       MetricPoint(
           attributes={
               "gen_ai.agent.name": "complex_agent",
               "gen_ai.tool.name": "get_current_time",
+              "gen_ai.tool.type": "FunctionTool",
           },
           value=None,
       ),
@@ -423,6 +425,7 @@ async def failing_tool():
           attributes={
               "gen_ai.agent.name": "error_agent",
               "gen_ai.tool.name": "failing_tool",
+              "gen_ai.tool.type": "FunctionTool",
               "error.type": "ValueError",
           },
           value=None,
@@ -431,6 +434,7 @@ async def failing_tool():
           attributes={
               "gen_ai.agent.name": "error_agent",
               "gen_ai.tool.name": "get_current_time",
+              "gen_ai.tool.type": "FunctionTool",
           },
           value=None,
       ),

tests/unittests/telemetry/test_metrics.py

@@ -169,6 +169,7 @@ def test_record_tool_execution_duration(mock_meter_setup):
   """Tests record_tool_execution_duration records correctly."""
   _metrics.record_tool_execution_duration(
       "test_tool",
+      "test_tool_type",
       "test_agent",
       0.5,
   )
@@ -179,6 +180,7 @@ def test_record_tool_execution_duration(mock_meter_setup):
   want_attributes = {
       "gen_ai.agent.name": "test_agent",
       "gen_ai.tool.name": "test_tool",
+      "gen_ai.tool.type": "test_tool_type",
   }
   assert kwargs["attributes"] == want_attributes
 
@@ -188,6 +190,7 @@ def test_record_tool_execution_duration_with_error(mock_meter_setup):
   test_error = ValueError("tool failed")
   _metrics.record_tool_execution_duration(
       "test_tool",
+      "test_tool_type",
       "test_agent",
       0.5,
       error=test_error,