browser.goto · MCP Playwright Browser MCP: Risk & Policy

WHAT IT DOES

What browser.goto does on MCP Playwright Browser

AI agents invoke browser.goto to trigger actions in MCP Playwright Browser. 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.goto needs a policy

Navigating to a URL causes the browser to make network requests, execute JavaScript on the target page, and potentially trigger side effects on remote systems. While it doesn't directly delete or move money, it executes an external operation and could be used to access sensitive resources or trigger server-side actions.

From the tool's definition Navigate to a URL — triggers external network requests and browser navigation, an external operation whose effects depend on the argument (the URL).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser.goto Rate-limited

browser.goto 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.goto": {
      "limits": [
        {
          "counter": "browser.goto_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 Playwright Browser, so you can run agents against it safely.

FAQ

Questions about browser.goto

What does the browser.goto tool do? +

Navigate to a URL. It is categorised as a Execute tool in the MCP Playwright Browser 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.goto? +

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

What risk level is browser.goto? +

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

Can I rate-limit browser.goto? +

Yes. Add a rate_limit block to the browser.goto 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.goto completely? +

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

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