High Risk →

browser_perform

Perform a task with the browser. It can click, type, export, capture screenshot, drag, hover, select options, etc.

How to control browser_perform ↓

AI agents invoke browser_perform to trigger actions in Fast 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.

High Risk

This tool executes arbitrary browser actions (clicks, typing, dragging, form interactions, exports) whose effects depend entirely on what is passed as arguments. It can trigger external operations, submit forms, interact with web applications, and cause side effects across any website the browser is navigating.

From the tool's definition Perform a task with the browser. It can click, type, export, capture screenshot, drag, hover, select options, etc.

Documented attack patterns abuse exactly the kind of access browser_perform gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and Fast Playwright MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_perform:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "browser_perform": {
      "limits": [
        {
          "counter": "browser_perform_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

browser_perform 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.

  1. Create a free account and register Fast Playwright MCP — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the browser_perform tool do? +

Perform a task with the browser. It can click, type, export, capture screenshot, drag, hover, select options, etc. It is categorised as a Execute tool in the Fast 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_perform? +

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

What risk level is browser_perform? +

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

Can I rate-limit browser_perform? +

Yes. Add a rate_limit block to the browser_perform 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_perform completely? +

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

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

Enforce policy on every Fast Playwright MCP tool call.

Deterministic rules across all 34 Fast Playwright MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

34 Fast Playwright MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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