Python error handling fix

Author: SteveSandersonMS

python/copilot/session.py

@@ -340,16 +340,27 @@ async def _execute_tool_and_respond(
             else:
                 tool_result = result  # type: ignore[assignment]
 
-            await self.rpc.tools.handle_pending_tool_call(
-                SessionToolsHandlePendingToolCallParams(
-                    request_id=request_id,
-                    result=ResultResult(
-                        text_result_for_llm=tool_result.text_result_for_llm,
-                        result_type=tool_result.result_type,
-                        tool_telemetry=tool_result.tool_telemetry,
-                    ),
+            # If the tool reported a failure with an error message, send it via the
+            # top-level error param so the server formats the tool message consistently
+            # with other SDKs (e.g., "Failed to execute 'tool' ... due to error: ...").
+            if tool_result.result_type == "failure" and tool_result.error:
+                await self.rpc.tools.handle_pending_tool_call(
+                    SessionToolsHandlePendingToolCallParams(
+                        request_id=request_id,
+                        error=tool_result.error,
+                    )
+                )
+            else:
+                await self.rpc.tools.handle_pending_tool_call(
+                    SessionToolsHandlePendingToolCallParams(
+                        request_id=request_id,
+                        result=ResultResult(
+                            text_result_for_llm=tool_result.text_result_for_llm,
+                            result_type=tool_result.result_type,
+                            tool_telemetry=tool_result.tool_telemetry,
+                        ),
+                    )
                 )
-            )
         except Exception as exc:
             try:
                 await self.rpc.tools.handle_pending_tool_call(

python/e2e/test_multi_client.py

@@ -436,7 +436,7 @@ def ephemeral_tool(params: InputParams, invocation: ToolInvocation) -> str:
         await mctx.client2.force_stop()
 
         # Give the server time to process the connection close
-        await asyncio.sleep(0.5)
+        await asyncio.sleep(2)
 
         # Recreate client2 for future tests (but don't rejoin the session)
         actual_port = mctx.client1.actual_port