diff --git a/agent/chat_completion_helpers.py b/agent/chat_completion_helpers.py
index 5485af6ce5..f2e98cdb3b 100644
--- a/agent/chat_completion_helpers.py
+++ b/agent/chat_completion_helpers.py
@@ -2075,6 +2075,8 @@ def _codex_summary_attempt(agent, api_messages: list, api_request_id: str):
     def _attempt(retry_count: int) -> str:
         codex_kwargs = agent._build_api_kwargs(api_messages)
         codex_kwargs.pop("tools", None)
+        codex_kwargs.pop("tool_choice", None)
+        codex_kwargs.pop("parallel_tool_calls", None)
         return _summary_text(agent, agent._run_codex_stream(codex_kwargs))
     return _attempt
 
diff --git a/tests/run_agent/test_run_agent.py b/tests/run_agent/test_run_agent.py
index a807fb7a6a..a470bf990b 100644
--- a/tests/run_agent/test_run_agent.py
+++ b/tests/run_agent/test_run_agent.py
@@ -2905,6 +2905,48 @@ class TestHandleMaxIterations:
             for item in input_items
         )
 
+    def test_codex_summary_strips_tool_controls_when_tools_removed(self, agent):
+        agent.api_mode = "codex_responses"
+        agent.provider = "openai-codex"
+        agent.base_url = "https://chatgpt.com/backend-api/codex"
+        agent._base_url_lower = agent.base_url.lower()
+        agent._base_url_hostname = "chatgpt.com"
+        agent.model = "gpt-5.5"
+        agent._cached_system_prompt = "You are helpful."
+        captured = {}
+
+        monkey_kwargs = {
+            "model": "gpt-5.5",
+            "input": [{"role": "user", "content": "do stuff"}],
+            "tools": [{"type": "function", "name": "web_search"}],
+            "tool_choice": "auto",
+            "parallel_tool_calls": True,
+        }
+
+        def fake_run_codex_stream(kwargs):
+            captured.update(kwargs)
+            return SimpleNamespace(
+                status="completed",
+                output=[
+                    SimpleNamespace(
+                        type="message",
+                        status="completed",
+                        content=[SimpleNamespace(type="output_text", text="Summary")],
+                    )
+                ],
+            )
+
+        with (
+            patch.object(agent, "_build_api_kwargs", return_value=monkey_kwargs.copy()),
+            patch.object(agent, "_run_codex_stream", side_effect=fake_run_codex_stream),
+        ):
+            result = agent._handle_max_iterations([{"role": "user", "content": "do stuff"}], 90)
+
+        assert result == "Summary"
+        assert "tools" not in captured
+        assert "tool_choice" not in captured
+        assert "parallel_tool_calls" not in captured
+
     def test_api_sanitizer_matches_responses_call_id_when_id_differs(self, agent):
         messages = [
             {