ai.screenshot · MCP: Risk & Policy

WHAT IT DOES

What ai.screenshot does on Mcp

AI agents invoke ai.screenshot to trigger actions in 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 ai.screenshot needs a policy

This tool launches a headless browser to navigate to an arbitrary URL and capture a screenshot — it executes external browser operations whose effects depend on the provided URL argument. It is not a simple read/fetch; it involves running browser automation.

From the tool's definition Take a headless-browser screenshot of a URL

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ai.screenshot Rate-limited

ai.screenshot 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": {
    "ai.screenshot": {
      "limits": [
        {
          "counter": "ai.screenshot_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 Mcp, so you can run agents against it safely.

FAQ

Questions about ai.screenshot

What does the ai.screenshot tool do? +

Take a headless-browser screenshot of a URL. Returns base64 image + size metadata. It is categorised as a Execute tool in the 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 ai.screenshot? +

Register the MCP server in PolicyLayer and add a rule for ai.screenshot: 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 Mcp. Nothing to install.

What risk level is ai.screenshot? +

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

Can I rate-limit ai.screenshot? +

Yes. Add a rate_limit block to the ai.screenshot 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 ai.screenshot completely? +

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

ai.screenshot is provided by the MCP server (@2sio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.