test: align MCP transient reconnect coverage

maintainer edit: update the existing transient retry tests for reconnect-first behavior and keep structured retry-failure coverage in the focused MCP transient suite.

tests/agent/test_mcp_transient_retry.py

@@ -16,6 +16,7 @@ from nanobot.agent.tools.mcp import (
     _is_session_terminated,
     _is_transient,
 )
+from nanobot.agent.tools.registry import is_tool_error_result
 
 # ---------------------------------------------------------------------------
 # _is_transient helper
@@ -134,6 +135,7 @@ async def test_tool_fails_after_retry_exhausted():
 
     assert "failed after retry" in output
     assert "ClosedResourceError" in output
+    assert is_tool_error_result(wrapper.name, output)
     assert session.call_tool.call_count == 2
 
 
@@ -237,12 +239,10 @@ async def test_tool_retry_on_end_of_stream():
 
 
 @pytest.mark.asyncio
-async def test_tool_reconnects_when_transient_retry_reveals_terminated_session():
-    """Tool should reconnect if a stale session reports termination after transient retry."""
+async def test_tool_reconnects_on_transient_failure():
+    """Tool should reconnect when a stale session reports a transient stream failure."""
     old_session = AsyncMock()
-    old_session.call_tool = AsyncMock(
-        side_effect=[_FakeClosedResourceError("closed"), _session_terminated_error()]
-    )
+    old_session.call_tool = AsyncMock(side_effect=_FakeClosedResourceError("closed"))
     new_session = AsyncMock()
     new_session.call_tool = AsyncMock(return_value=_make_tool_result("fresh"))
 
@@ -257,12 +257,13 @@ async def test_tool_reconnects_when_transient_retry_reveals_terminated_session()
 
     wrapper.set_reconnect_handler(reconnect)
 
-    with patch("nanobot.agent.tools.mcp.asyncio.sleep", new_callable=AsyncMock):
+    with patch("nanobot.agent.tools.mcp.asyncio.sleep", new_callable=AsyncMock) as mock_sleep:
         output = await wrapper.execute(foo="bar")
 
     assert output == "fresh"
-    assert old_session.call_tool.call_count == 2
+    assert old_session.call_tool.call_count == 1
     assert new_session.call_tool.call_count == 1
+    mock_sleep.assert_not_called()
 
 
 # ---------------------------------------------------------------------------

tests/tools/test_mcp_tool.py

@@ -478,61 +478,6 @@ async def test_execute_handles_generic_exception() -> None:
     assert is_tool_error_result(wrapper.name, result)
 
 
-@pytest.mark.asyncio
-async def test_execute_reconnects_on_transient_failure() -> None:
-    class ClosedResourceError(Exception):
-        pass
-
-    reconnects = 0
-
-    async def stale_call_tool(_name: str, arguments: dict) -> object:
-        raise ClosedResourceError("stream closed")
-
-    async def fresh_call_tool(_name: str, arguments: dict) -> object:
-        return SimpleNamespace(content=[_FakeTextContent("ok")])
-
-    wrapper = _make_wrapper(SimpleNamespace(call_tool=stale_call_tool))
-
-    async def reconnect(_server_name: str, _tool_name: str, _stale_tool: object) -> object:
-        nonlocal reconnects
-        reconnects += 1
-        return SimpleNamespace(_session=SimpleNamespace(call_tool=fresh_call_tool))
-
-    wrapper.set_reconnect_handler(reconnect)
-
-    result = await wrapper.execute()
-
-    assert result == "ok"
-    assert reconnects == 1
-
-
-@pytest.mark.asyncio
-async def test_execute_marks_transient_retry_failure_as_tool_error(
-    monkeypatch: pytest.MonkeyPatch,
-) -> None:
-    class ClosedResourceError(Exception):
-        pass
-
-    calls = 0
-
-    async def call_tool(_name: str, arguments: dict) -> object:
-        nonlocal calls
-        calls += 1
-        raise ClosedResourceError("closed")
-
-    async def fast_sleep(_delay: float) -> None:
-        return None
-
-    monkeypatch.setattr(mcp_mod.asyncio, "sleep", fast_sleep)
-    wrapper = _make_wrapper(SimpleNamespace(call_tool=call_tool))
-
-    result = await wrapper.execute()
-
-    assert calls == 2
-    assert result == "(MCP tool call failed after retry: ClosedResourceError)"
-    assert is_tool_error_result(wrapper.name, result)
-
-
 def _make_tool_def(name: str) -> SimpleNamespace:
     return SimpleNamespace(
         name=name,