diff --git a/backend/apps/agents/agent_manager.py b/backend/apps/agents/agent_manager.py
index 8095c647..97b0f39f 100644
--- a/backend/apps/agents/agent_manager.py
+++ b/backend/apps/agents/agent_manager.py
@@ -26,7 +26,7 @@ from backend.apps.agents.manager.SessionControlMixin import SessionControlMixin
 from backend.apps.agents.manager.AgentLaunchMixin import AgentLaunchMixin
 from backend.apps.agents.manager.MockAgentMixin import MockAgentMixin
 from backend.apps.agents.manager.RunSupportMixin import RunSupportMixin
-from backend.apps.agents.manager.run.error_cards import handle_run_error
+from backend.apps.agents.manager.run.handle_run_error import handle_run_error
 from backend.apps.agents.manager.run.TurnRunnerMixin import TurnRunnerMixin
 from backend.apps.agents.manager.run.RunOptionsMixin import RunOptionsMixin
 
diff --git a/backend/apps/agents/manager/builtin_mcp_servers.py b/backend/apps/agents/manager/register_builtin_mcp_servers.py
similarity index 100%
rename from backend/apps/agents/manager/builtin_mcp_servers.py
rename to backend/apps/agents/manager/register_builtin_mcp_servers.py
diff --git a/backend/apps/agents/manager/run/RunOptionsMixin.py b/backend/apps/agents/manager/run/RunOptionsMixin.py
index d1467ca4..67ecd016 100644
--- a/backend/apps/agents/manager/run/RunOptionsMixin.py
+++ b/backend/apps/agents/manager/run/RunOptionsMixin.py
@@ -19,7 +19,7 @@ from backend.apps.agents.manager.streaming import tool_result_hook
 from backend.apps.agents.manager.streaming import stop_hook as stop_hook_mod
 from backend.apps.agents.manager.streaming.hook_context import HookContext
 from backend.apps.agents.manager.permissions.effective_tools import build_effective_tool_lists
-from backend.apps.agents.manager.builtin_mcp_servers import register_builtin_mcp_servers
+from backend.apps.agents.manager.register_builtin_mcp_servers import register_builtin_mcp_servers
 from backend.apps.agents.manager.provider_env import configure_provider_env
 from backend.apps.agents.manager.session.workspace_git import ensure_cwd_git_repo
 from backend.apps.agents.manager.session.history_compaction import build_history_prefix, get_branch_messages
diff --git a/backend/apps/agents/manager/run/error_cards.py b/backend/apps/agents/manager/run/handle_run_error.py
similarity index 99%
rename from backend/apps/agents/manager/run/error_cards.py
rename to backend/apps/agents/manager/run/handle_run_error.py
index 327302b2..29d2b5cf 100644
--- a/backend/apps/agents/manager/run/error_cards.py
+++ b/backend/apps/agents/manager/run/handle_run_error.py
@@ -89,7 +89,7 @@ async def handle_run_error(e: Exception, session: AgentSession, session_id: str,
             from backend.apps.service.client import submit_diagnostic
             submit_diagnostic({
                 "kind": "context_overflow",
-                "where": "manager.run.error_cards.handle_run_error",
+                "where": "manager.run.handle_run_error",
                 "session_id": session_id,
                 "model": session.model,
                 "provider": session.provider,
diff --git a/backend/tests/test_builtin_mcp_servers.py b/backend/tests/test_register_builtin_mcp_servers.py
similarity index 95%
rename from backend/tests/test_builtin_mcp_servers.py
rename to backend/tests/test_register_builtin_mcp_servers.py
index 66eea134..be6d8a93 100644
--- a/backend/tests/test_builtin_mcp_servers.py
+++ b/backend/tests/test_register_builtin_mcp_servers.py
@@ -5,7 +5,7 @@ fully denied, and the delegation tool-name lists come back for the allowlist gat
 import os
 
 from backend.apps.agents.core.models import AgentSession
-from backend.apps.agents.manager.builtin_mcp_servers import register_builtin_mcp_servers
+from backend.apps.agents.manager.register_builtin_mcp_servers import register_builtin_mcp_servers
 
 
 def p_session():