stop_trace

What stop_trace does on Unreal

AI agents invoke stop_trace to trigger actions in Unreal. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

Why stop_trace is rated High

This tool triggers an operation that stops a live trace session in Unreal Engine's profiling infrastructure. While not permanently destructive (the trace data already collected typically persists), it executes a command that halts an ongoing external process. This is an Execute action rather than Read (it modifies system state) or Destructive (the action is reversible—a new trace can be started).

From the tool's definition 'Stop the active Unreal Insights trace session' - this terminates an active tracing operation, which is an externally-observable action that affects the state of a running profiling/debugging system.

The rule that runs stop_trace safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Unreal, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For stop_trace, this is the rule to start with:

{
  "version": "1",
  "default": "deny",
  "tools": {
    "stop_trace": {
      "limits": [
        {
          "counter": "stop_trace_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

Questions about stop_trace