browser_video_start · Playwright MCP: Risk & Policy

WHAT IT DOES

What browser_video_start does on Playwright MCP

AI agents invoke browser_video_start to trigger actions in Playwright 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 browser_video_start needs a policy

This tool triggers an external recording operation on the browser, which is an Execute-class action. It does not destructively delete data (Destructive), move money (Financial), or simply retrieve data (Read). While it does create a recording artifact, the primary action is executing a recording process.

From the tool's definition Tool name and description: 'Start recording a video of browser interactions. The video will capture all page activities until stopped.' This initiates an external operation (video recording) whose effects depend on browser state and user arguments, and the…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_video_start Rate-limited

browser_video_start 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": {
    "browser_video_start": {
      "limits": [
        {
          "counter": "browser_video_start_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 Playwright MCP, so you can run agents against it safely.

FAQ

Questions about browser_video_start

What does the browser_video_start tool do? +

Start recording a video of browser interactions. The video will capture all page activities until stopped. It is categorised as a Execute tool in the Playwright 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 browser_video_start? +

Register the Playwright MCP server in PolicyLayer and add a rule for browser_video_start: 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 Playwright MCP. Nothing to install.

What risk level is browser_video_start? +

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

Can I rate-limit browser_video_start? +

Yes. Add a rate_limit block to the browser_video_start 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 browser_video_start completely? +

Set action: deny in the PolicyLayer policy for browser_video_start. 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 browser_video_start? +

browser_video_start is provided by the Playwright MCP server (lewisvoncken/playwright-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.