browser_start_video · Playwright MCP: Risk & Policy

WHAT IT DOES

What browser_start_video does on Playwright MCP

AI agents invoke browser_start_video 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_start_video needs a policy

Although the description is empty (lowering confidence slightly), the tool name and context as part of Playwright browser automation indicates it executes an external operation (video capture) whose effects depend on arguments and system state. This is Execute rather than Write because it triggers a subprocess/external mechanism rather than simply modifying managed data structures.

From the tool's definition Tool name 'browser_start_video' suggests initiating video recording/capture functionality within a browser context.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_start_video Rate-limited

browser_start_video 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_start_video": {
      "limits": [
        {
          "counter": "browser_start_video_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_start_video

What does the browser_start_video tool do? +

browser_start_video. 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_start_video? +

Register the Playwright MCP server in PolicyLayer and add a rule for browser_start_video: 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_start_video? +

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

Can I rate-limit browser_start_video? +

Yes. Add a rate_limit block to the browser_start_video 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_start_video completely? +

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

browser_start_video is provided by the Playwright MCP server (roshan571/playwright-mcp2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.