performance_stop_trace · Opera DevTools MCP: Risk & Policy

WHAT IT DOES

What performance_stop_trace does on Opera DevTools MCP

AI agents invoke performance_stop_trace to trigger actions in Opera 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 executes a DevTools command that modifies the browser's profiling/tracing state. While stopping a trace is not inherently destructive (the trace data persists), it is an Execute action because it runs an external operation on the browser with side effects.

From the tool's definition Tool performs a browser action ('Stop the active performance trace recording') via DevTools control. It triggers an external operation (stopping an active recording session) whose effects are state-dependent and not reversible without manual restart.

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 Opera DevTools MCP, so you can run agents against it safely.

FAQ

Questions about performance_stop_trace

What does the performance_stop_trace tool do? +

Stop the active performance trace recording on the selected webpage. It is categorised as a Execute tool in the Opera 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 Opera 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 Opera 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 Opera DevTools MCP server (operasoftware/opera-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.