diff --git a/claude_agent_pipe.py b/claude_agent_pipe.py
index 8da0ed1..7000f49 100644
--- a/claude_agent_pipe.py
+++ b/claude_agent_pipe.py
@@ -369,8 +369,8 @@ def _build_kb_mcp_server(
     user_dict: Optional[Dict[str, Any]] = None,
     event_emitter: Optional[Callable] = None,
 ):
-    """Return (mcp_config, tool_names) for a knowledge-base search tool Claude
-    can invoke, or (None, []) if no KBs are attached.
+    """Return (mcp_config, tool_names, tools_by_name) for a knowledge-base
+    search tool Claude can invoke, or (None, [], {}) if no KBs are attached.
 
     Result formatting follows OpenWebUI's native RAG shape (<source id=N ...>
     tags + citation event), so Claude's replies render with inline [N]
@@ -379,7 +379,7 @@ def _build_kb_mcp_server(
     that OpenWebUI's middleware already filtered by the user's grants.
     """
     if not knowledge:
-        return None, []
+        return None, [], {}
 
     collection_names = [k["id"] for k in knowledge]
     display = ", ".join(k["name"] for k in knowledge)