address review comments

Author: krisztianfekete

src/agentevals/converter.py

@@ -157,7 +157,7 @@ def _walk(span: Span, op_prefix: str, acc: list[Span]) -> None:
 
 
 def _extract_user_content(first_call_llm: Span) -> genai_types.Content:
-    """Extract user input from the first call_llm span's llm_request tag."""
+    """Extract user input from the first call_llm span's attributes via shared extractor."""
     text = extract_user_text_from_attrs(first_call_llm.tags)
     if text:
         return genai_types.Content(
@@ -173,7 +173,7 @@ def _extract_user_content(first_call_llm: Span) -> genai_types.Content:
 
 
 def _extract_final_response(last_call_llm: Span) -> genai_types.Content:
-    """Extract final text response from the last call_llm span's llm_response tag."""
+    """Extract final text response from the last call_llm span's attributes via shared extractor."""
     text = extract_agent_response_from_attrs(last_call_llm.tags)
     if text:
         return genai_types.Content(

src/agentevals/genai_converter.py

@@ -317,7 +317,9 @@ def _extract_user_text(llm_span: Span) -> str:
     text = extract_user_text_from_attrs(llm_span.tags)
     if text:
         return text
-    raise ValueError(f"LLM span {llm_span.span_id}: no user message found in span attributes")
+    raise ValueError(
+        f"LLM span {llm_span.span_id}: no user message found (checked gen_ai.input.messages and ADK llm_request)"
+    )
 
 
 def _extract_assistant_text(llm_span: Span) -> str:

tests/test_extraction.py

@@ -194,6 +194,17 @@ def test_adk_no_text_parts(self):
         attrs = {ADK_LLM_RESPONSE: json.dumps({"content": {"parts": [{"function_call": {"name": "tool"}}]}})}
         assert extract_agent_response_from_attrs(attrs) is None
 
+    def test_genai_prefers_last_assistant(self):
+        attrs = {
+            OTEL_GENAI_OUTPUT_MESSAGES: json.dumps(
+                [
+                    {"role": "assistant", "content": "First response"},
+                    {"role": "assistant", "content": "Second response"},
+                ]
+            )
+        }
+        assert extract_agent_response_from_attrs(attrs) == "Second response"
+
 
 # ---------------------------------------------------------------------------
 # extract_token_usage_from_attrs