diff --git a/tests/unit/proxy/_experimental/mcp_server/test_openapi_tool_auth.py b/tests/unit/proxy/_experimental/mcp_server/test_openapi_tool_auth.py
index 60157193a16..c570d498f44 100644
--- a/tests/unit/proxy/_experimental/mcp_server/test_openapi_tool_auth.py
+++ b/tests/unit/proxy/_experimental/mcp_server/test_openapi_tool_auth.py
@@ -48,6 +48,7 @@ async def test_openapi_local_tool_runs_pre_call_tool_check():
     fake_tool.name = "list_pets"
     fake_tool.description = "test tool"
     fake_tool.input_schema = {"type": "object"}
+    fake_tool.server_id = fake_server.server_id
 
     pre_call = AsyncMock(return_value={})
     handle_local = AsyncMock(return_value=CallToolResult(content=[], is_error=False))
@@ -134,6 +135,7 @@ async def test_openapi_local_tool_blocked_when_pre_call_check_raises():
     fake_tool.name = "delete_pet"
     fake_tool.description = "test tool"
     fake_tool.input_schema = {"type": "object"}
+    fake_tool.server_id = fake_server.server_id
 
     pre_call = AsyncMock(
         side_effect=HTTPException(status_code=403, detail="not allowed")
@@ -284,6 +286,7 @@ async def test_openapi_local_tool_injects_resolved_oauth_token():
     fake_tool.name = "get_values"
     fake_tool.description = "test tool"
     fake_tool.input_schema = {"type": "object"}
+    fake_tool.server_id = oauth_server.server_id
     captured: dict = {}
 
     async def handle_local(_name, _arguments, _wire_compat):
@@ -632,6 +635,7 @@ async def test_per_server_auth_header_reaches_both_openapi_dispatch_arms(dispatc
             fake_tool.name = "list_reports"
             fake_tool.description = "test tool"
             fake_tool.input_schema = {"type": "object"}
+            fake_tool.server_id = server.server_id
             with (
                 patch.object(manager, "_get_mcp_server_from_tool_name", return_value=server),
                 patch.object(mcp_operations.global_mcp_tool_registry, "get_tool", return_value=fake_tool),
@@ -705,6 +709,7 @@ async def test_local_dispatch_reports_the_outcome_instead_of_success(failure: st
     fake_tool.name = "list_reports"
     fake_tool.description = "test tool"
     fake_tool.input_schema = {"type": "object"}
+    fake_tool.server_id = None
     fake_tool.handler = raising_handler
     server = MCPServer(
         server_id="srv-openapi",