fix: set execute_tool {tool.name} span attributes even when exception occurs during tool's execution

PiperOrigin-RevId: 824165197

src/google/adk/flows/llm_flows/functions.py

@@ -305,7 +305,9 @@ async def _execute_single_function_call_async(
     else:
       raise tool_error
 
-  with tracer.start_as_current_span(f'execute_tool {tool.name}'):
+  async def _run_with_trace():
+    nonlocal function_args
+
     # Step 1: Check if plugin before_tool_callback overrides the function
     # response.
     function_response = (
@@ -391,13 +393,23 @@ async def _execute_single_function_call_async(
     function_response_event = __build_response_event(
         tool, function_response, tool_context, invocation_context
     )
-    trace_tool_call(
-        tool=tool,
-        args=function_args,
-        function_response_event=function_response_event,
-    )
     return function_response_event
 
+  with tracer.start_as_current_span(f'execute_tool {tool.name}'):
+    try:
+      function_response_event = await _run_with_trace()
+      trace_tool_call(
+          tool=tool,
+          args=function_args,
+          function_response_event=function_response_event,
+      )
+      return function_response_event
+    except:
+      trace_tool_call(
+          tool=tool, args=function_args, function_response_event=None
+      )
+      raise
+
 
 async def handle_function_calls_live(
     invocation_context: InvocationContext,
@@ -467,13 +479,17 @@ async def _execute_single_function_call_live(
   tool, tool_context = _get_tool_and_context(
       invocation_context, function_call, tools_dict
   )
-  with tracer.start_as_current_span(f'execute_tool {tool.name}'):
+
+  function_args = (
+      copy.deepcopy(function_call.args) if function_call.args else {}
+  )
+
+  async def _run_with_trace():
+    nonlocal function_args
+
     # Do not use "args" as the variable name, because it is a reserved keyword
     # in python debugger.
     # Make a deep copy to avoid being modified.
-    function_args = (
-        copy.deepcopy(function_call.args) if function_call.args else {}
-    )
     function_response = None
 
     # Handle before_tool_callbacks - iterate through the canonical callback
@@ -527,13 +543,23 @@ async def _execute_single_function_call_live(
     function_response_event = __build_response_event(
         tool, function_response, tool_context, invocation_context
     )
-    trace_tool_call(
-        tool=tool,
-        args=function_args,
-        function_response_event=function_response_event,
-    )
     return function_response_event
 
+  with tracer.start_as_current_span(f'execute_tool {tool.name}'):
+    try:
+      function_response_event = await _run_with_trace()
+      trace_tool_call(
+          tool=tool,
+          args=function_args,
+          function_response_event=function_response_event,
+      )
+      return function_response_event
+    except:
+      trace_tool_call(
+          tool=tool, args=function_args, function_response_event=None
+      )
+      raise
+
 
 async def _process_function_live_helper(
     tool,

src/google/adk/telemetry/tracing.py

@@ -26,6 +26,7 @@ from __future__ import annotations
 import json
 import os
 from typing import Any
+from typing import Optional
 from typing import TYPE_CHECKING
 
 from google.genai import types
@@ -118,7 +119,7 @@ def trace_agent_invocation(
 def trace_tool_call(
     tool: BaseTool,
     args: dict[str, Any],
-    function_response_event: Event,
+    function_response_event: Optional[Event],
 ):
   """Traces tool call.
 
@@ -154,7 +155,8 @@ def trace_tool_call(
   tool_call_id = '<not specified>'
   tool_response = '<not specified>'
   if (
-      function_response_event.content is not None
+      function_response_event is not None
+      and function_response_event.content is not None
       and function_response_event.content.parts
   ):
     response_parts = function_response_event.content.parts
@@ -169,7 +171,8 @@ def trace_tool_call(
 
   if not isinstance(tool_response, dict):
     tool_response = {'result': tool_response}
-  span.set_attribute('gcp.vertex.agent.event_id', function_response_event.id)
+  if function_response_event is not None:
+    span.set_attribute('gcp.vertex.agent.event_id', function_response_event.id)
   if _should_add_request_response_to_spans():
     span.set_attribute(
         'gcp.vertex.agent.tool_response',

tests/unittests/telemetry/test_functional.py

@@ -12,18 +12,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import asyncio
 import gc
 import sys
-from unittest import mock
 
 from google.adk.agents import base_agent
 from google.adk.agents.llm_agent import Agent
 from google.adk.models.base_llm import BaseLlm
+from google.adk.models.llm_response import LlmResponse
 from google.adk.telemetry import tracing
 from google.adk.tools import FunctionTool
 from google.adk.utils.context_utils import Aclosing
+from google.genai.types import Content
 from google.genai.types import Part
-from opentelemetry.version import __version__
+from opentelemetry.sdk.trace import TracerProvider
+from opentelemetry.sdk.trace.export import SimpleSpanProcessor
+from opentelemetry.sdk.trace.export.in_memory_span_exporter import InMemorySpanExporter
 import pytest
 
 from ..testing_utils import MockModel
@@ -63,27 +67,27 @@ async def test_runner(test_agent: Agent) -> TestInMemoryRunner:
 
 
 @pytest.fixture
-def mock_start_as_current_span(monkeypatch: pytest.MonkeyPatch) -> mock.Mock:
-  mock_context_manager = mock.MagicMock()
-  mock_context_manager.__enter__.return_value = mock.Mock()
-  mock_start_as_current_span = mock.Mock()
-  mock_start_as_current_span.return_value = mock_context_manager
+def span_exporter(monkeypatch: pytest.MonkeyPatch) -> InMemorySpanExporter:
+  tracer_provider = TracerProvider()
+  span_exporter = InMemorySpanExporter()
+  tracer_provider.add_span_processor(SimpleSpanProcessor(span_exporter))
+  real_tracer = tracer_provider.get_tracer(__name__)
 
   def do_replace(tracer):
     monkeypatch.setattr(
-        tracer, 'start_as_current_span', mock_start_as_current_span
+        tracer, 'start_as_current_span', real_tracer.start_as_current_span
     )
 
   do_replace(tracing.tracer)
   do_replace(base_agent.tracer)
 
-  return mock_start_as_current_span
+  return span_exporter
 
 
 @pytest.mark.asyncio
 async def test_tracer_start_as_current_span(
     test_runner: TestInMemoryRunner,
-    mock_start_as_current_span: mock.Mock,
+    span_exporter: InMemorySpanExporter,
 ):
   """Test creation of multiple spans in an E2E runner invocation.
 
@@ -112,18 +116,49 @@ async def test_tracer_start_as_current_span(
       pass
 
   # Assert
-  expected_start_as_current_span_calls = [
-      mock.call('invocation'),
-      mock.call('execute_tool some_tool'),
-      mock.call('invoke_agent some_root_agent'),
-      mock.call('call_llm'),
-      mock.call('call_llm'),
+  spans = span_exporter.get_finished_spans()
+  assert list(sorted(span.name for span in spans)) == [
+      'call_llm',
+      'call_llm',
+      'execute_tool some_tool',
+      'invocation',
+      'invoke_agent some_root_agent',
   ]
 
-  mock_start_as_current_span.assert_has_calls(
-      expected_start_as_current_span_calls,
-      any_order=True,
+
+@pytest.mark.asyncio
+async def test_exception_preserves_attributes(
+    test_model: BaseLlm, span_exporter: InMemorySpanExporter
+):
+  """Test when an exception occurs during tool execution, span attributes are still present on spans where they are expected."""
+
+  # Arrange
+  async def some_tool():
+    raise ValueError('This tool always fails')
+
+  test_agent = Agent(
+      name='some_root_agent',
+      model=test_model,
+      tools=[
+          FunctionTool(some_tool),
+      ],
   )
-  assert mock_start_as_current_span.call_count == len(
-      expected_start_as_current_span_calls
+
+  test_runner = TestInMemoryRunner(test_agent)
+
+  # Act
+  with pytest.raises(ValueError, match='This tool always fails'):
+    async with Aclosing(
+        test_runner.run_async_with_new_session_agen('')
+    ) as agen:
+      async for _ in agen:
+        pass
+
+  # Assert
+  spans = span_exporter.get_finished_spans()
+  assert len(spans) > 1
+  assert all(
+      span.attributes is not None and len(span.attributes) > 0
+      for span in spans
+      if span.name != 'invocation'  # not expected to have attributes
   )