Merge origin/main into pr-27248 (resolving run_agent.py = ours)

run_agent.py taken from HEAD (the extracted forwarder structure). The 25
run_agent.py fixes that landed on main during the PR's life need to be
ported into the agent/* extracted modules in follow-up commits.

tests/run_agent/test_run_agent.py

@@ -2269,6 +2269,60 @@ class TestParallelScopePathNormalization:
         assert not _should_parallelize_tool_batch([tc1, tc2])
 
 
+class TestMcpParallelToolBatch:
+    """Integration test: _should_parallelize_tool_batch respects MCP parallel flag."""
+
+    def test_mcp_tools_default_sequential(self):
+        """MCP tools without supports_parallel_tool_calls are sequential."""
+        from run_agent import _should_parallelize_tool_batch
+        tc1 = _mock_tool_call(name="mcp_github_list_repos", arguments='{"org":"openai"}', call_id="c1")
+        tc2 = _mock_tool_call(name="mcp_github_search_code", arguments='{"q":"test"}', call_id="c2")
+        assert not _should_parallelize_tool_batch([tc1, tc2])
+
+    def test_mcp_tools_parallel_when_server_opted_in(self):
+        """MCP tools from a parallel-safe server can run concurrently."""
+        from run_agent import _should_parallelize_tool_batch
+        from tools.mcp_tool import _parallel_safe_servers, _lock
+        with _lock:
+            _parallel_safe_servers.add("github")
+        try:
+            tc1 = _mock_tool_call(name="mcp_github_list_repos", arguments='{"org":"openai"}', call_id="c1")
+            tc2 = _mock_tool_call(name="mcp_github_search_code", arguments='{"q":"test"}', call_id="c2")
+            assert _should_parallelize_tool_batch([tc1, tc2])
+        finally:
+            with _lock:
+                _parallel_safe_servers.discard("github")
+
+    def test_mixed_mcp_and_builtin_parallel(self):
+        """MCP parallel tools mixed with built-in parallel-safe tools."""
+        from run_agent import _should_parallelize_tool_batch
+        from tools.mcp_tool import _parallel_safe_servers, _lock
+        with _lock:
+            _parallel_safe_servers.add("docs")
+        try:
+            tc1 = _mock_tool_call(name="mcp_docs_search", arguments='{"query":"api"}', call_id="c1")
+            tc2 = _mock_tool_call(name="web_search", arguments='{"query":"test"}', call_id="c2")
+            assert _should_parallelize_tool_batch([tc1, tc2])
+        finally:
+            with _lock:
+                _parallel_safe_servers.discard("docs")
+
+    def test_mixed_parallel_and_serial_mcp_servers(self):
+        """One parallel MCP server + one non-parallel MCP server = sequential."""
+        from run_agent import _should_parallelize_tool_batch
+        from tools.mcp_tool import _parallel_safe_servers, _lock
+        with _lock:
+            _parallel_safe_servers.add("docs")
+            # "github" is NOT in _parallel_safe_servers
+        try:
+            tc1 = _mock_tool_call(name="mcp_docs_search", arguments='{"query":"api"}', call_id="c1")
+            tc2 = _mock_tool_call(name="mcp_github_list_repos", arguments='{"org":"openai"}', call_id="c2")
+            assert not _should_parallelize_tool_batch([tc1, tc2])
+        finally:
+            with _lock:
+                _parallel_safe_servers.discard("docs")
+
+
 class TestHandleMaxIterations:
     def test_returns_summary(self, agent):
         resp = _mock_response(content="Here is a summary of what I did.")
@@ -2524,8 +2578,9 @@ class TestRunConversation:
         assert [call["api_call_count"] for call in pre_request_calls] == [1, 2]
         assert [call["api_call_count"] for call in post_request_calls] == [1, 2]
         assert all(call["session_id"] == agent.session_id for call in pre_request_calls)
-        assert all("message_count" in c and "messages" not in c for c in pre_request_calls)
-        assert all("usage" in c and "response" not in c for c in post_request_calls)
+        assert all("message_count" in c and isinstance(c.get("request_messages"), list) for c in pre_request_calls)
+        assert any(msg.get("role") == "user" and msg.get("content") == "search something" for msg in pre_request_calls[0]["request_messages"])
+        assert all("usage" in c and "response" in c and "assistant_message" in c for c in post_request_calls)
 
     def test_content_with_tool_calls_stays_silent_for_non_cli_quiet_mode(self, agent):
         self._setup_agent(agent)
@@ -3691,6 +3746,37 @@ class TestCredentialPoolRecovery:
         assert retry_same is False
         agent._swap_credential.assert_called_once_with(next_entry)
 
+    def test_recover_with_pool_rotates_usage_limit_429_immediately(self, agent):
+        next_entry = SimpleNamespace(label="secondary")
+        captured = {}
+
+        class _Pool:
+            def current(self):
+                return SimpleNamespace(label="primary")
+
+            def mark_exhausted_and_rotate(self, *, status_code, error_context=None):
+                captured["status_code"] = status_code
+                captured["error_context"] = error_context
+                return next_entry
+
+        agent._credential_pool = _Pool()
+        agent._swap_credential = MagicMock()
+
+        recovered, retry_same = agent._recover_with_credential_pool(
+            status_code=429,
+            has_retried_429=False,
+            error_context={
+                "reason": "usage_limit_reached",
+                "message": "The usage limit has been reached",
+            },
+        )
+
+        assert recovered is True
+        assert retry_same is False
+        assert captured["status_code"] == 429
+        assert captured["error_context"]["reason"] == "usage_limit_reached"
+        agent._swap_credential.assert_called_once_with(next_entry)
+
 
     def test_recover_with_pool_refreshes_on_401(self, agent):
         """401 with successful refresh should swap to refreshed credential."""
@@ -3777,6 +3863,22 @@ class TestCredentialPoolRecovery:
         assert context["message"] == "Weekly credits exhausted."
         assert context["reset_at"] == "2026-04-12T10:30:00Z"
 
+    def test_extract_api_error_context_uses_type_as_reason(self, agent):
+        error = SimpleNamespace(
+            body={
+                "error": {
+                    "type": "usage_limit_reached",
+                    "message": "The usage limit has been reached",
+                }
+            },
+            response=SimpleNamespace(headers={}),
+        )
+
+        context = agent._extract_api_error_context(error)
+
+        assert context["reason"] == "usage_limit_reached"
+        assert context["message"] == "The usage limit has been reached"
+
     def test_recover_with_pool_passes_error_context_on_rotated_429(self, agent):
         next_entry = SimpleNamespace(label="secondary")
         captured = {}