Let me explain how messages get processed. OpenClaw uses a lane queue system. By default, each agent processes messages serially. One message in, one response out, then the next message. Why? This prevents race conditions where 2 messages trigger conflicting actions.
For low-risk operations (like read-only lookups), you can mark specific tools as parallel-safe. The Gateway then processes those tool calls concurrently while keeping everything else serial. Be conservative here. If you mark a tool as parallel-safe when it has side effects, you'll get corrupted state that's painful to debug.