performance_stop_trace · Chrome DevTools MCP: Risk & Policy

WHAT IT DOES

What performance_stop_trace does on Chrome DevTools MCP

AI agents invoke performance_stop_trace to trigger actions in Chrome DevTools MCP. 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 IT NEEDS A POLICY

Why performance_stop_trace needs a policy

This tool triggers an action that stops an ongoing performance profiling operation. While not destructive (the trace data itself is not deleted, only recording is halted), it is an active operation control rather than a passive read. It qualifies as Execute because it triggers a state change in the browser's debugging infrastructure whose effects (terminating trace collection) depend on the current browser context.

From the tool's definition Tool description: 'Stops the active performance trace recording on the selected page.' The tool modifies the state of an active debugging/instrumentation operation on the browser, stopping a trace that was actively recording.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

performance_stop_trace Rate-limited

performance_stop_trace stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

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

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Chrome DevTools MCP, so you can run agents against it safely.

FAQ

Questions about performance_stop_trace

What does the performance_stop_trace tool do? +

Stops the active performance trace recording on the selected page. It is categorised as a Execute tool in the Chrome DevTools MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on performance_stop_trace? +

Register the Chrome DevTools MCP server in PolicyLayer and add a rule for performance_stop_trace: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Chrome DevTools MCP. Nothing to install.

What risk level is performance_stop_trace? +

performance_stop_trace is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit performance_stop_trace? +

Yes. Add a rate_limit block to the performance_stop_trace rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block performance_stop_trace completely? +

Set action: deny in the PolicyLayer policy for performance_stop_trace. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides performance_stop_trace? +

performance_stop_trace is provided by the Chrome DevTools MCP server (shay5555-gif/chrome-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.