diff --git a/src/core/services/tool_call_handlers/pytest_full_suite_handler.py b/src/core/services/tool_call_handlers/pytest_full_suite_handler.py
index c15a82a6..35ad4515 100644
--- a/src/core/services/tool_call_handlers/pytest_full_suite_handler.py
+++ b/src/core/services/tool_call_handlers/pytest_full_suite_handler.py
@@ -13,6 +13,7 @@
 
 import logging
 import re
+from collections.abc import Sequence
 from dataclasses import dataclass
 from pathlib import Path
 from typing import Any
@@ -81,7 +82,11 @@ def _extract_command(arguments: Any) -> str | None:
 
         return None
 
-    if isinstance(arguments, list):
+    if (
+        isinstance(arguments, Sequence)
+        and not isinstance(arguments, str | bytes)
+        and arguments
+    ):
         return " ".join(str(item) for item in arguments)
 
     return None
diff --git a/tests/unit/core/services/tool_call_handlers/test_pytest_full_suite_handler.py b/tests/unit/core/services/tool_call_handlers/test_pytest_full_suite_handler.py
index 11ddf82c..f9a85cd4 100644
--- a/tests/unit/core/services/tool_call_handlers/test_pytest_full_suite_handler.py
+++ b/tests/unit/core/services/tool_call_handlers/test_pytest_full_suite_handler.py
@@ -143,6 +143,24 @@ async def test_handler_detects_list_based_command() -> None:
     assert result.should_swallow is True
 
 
+@pytest.mark.asyncio
+async def test_handler_detects_tuple_arguments_root_level() -> None:
+    handler = PytestFullSuiteHandler(enabled=True)
+    context = ToolCallContext(
+        session_id="session-tuple",
+        backend_name="backend",
+        model_name="model",
+        full_response={},
+        tool_name="bash",
+        tool_arguments=("pytest", "-q"),
+    )
+
+    assert await handler.can_handle(context) is True
+    result = await handler.handle(context)
+
+    assert result.should_swallow is True
+
+
 @pytest.mark.asyncio
 async def test_handler_enabled_flag_controls_behavior() -> None:
     handler = PytestFullSuiteHandler(enabled=False)