High Risk →

browser_fill_form

Fill multiple form fields in one call. Fields can be addressed by ref (from snapshot) or by label (accessible name). Supports text inputs, checkboxes, radio buttons, and dropdowns. Handles progressive disclosure with brief pauses between fills.

How to control browser_fill_form ↓

What browser_fill_form does on Playwright Autopilot

AI agents invoke browser_fill_form to trigger actions in Playwright Autopilot. 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

Why browser_fill_form needs a policy

This tool performs browser interactions (filling forms) that trigger real side effects in an external browser/web application. Submitting or populating forms can trigger backend actions, data changes, or transactions depending on context. Since it drives live browser automation, it falls under Execute.

From the tool's definition Fill multiple form fields in one call...Supports text inputs, checkboxes, radio buttons, and dropdowns. Handles progressive disclosure with brief pauses between fills.

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

How to control browser_fill_form

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

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

browser_fill_form 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 Playwright Autopilot — 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 →

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Related tools and policies

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Questions about browser_fill_form

What does the browser_fill_form tool do? +

Fill multiple form fields in one call. Fields can be addressed by ref (from snapshot) or by label (accessible name). Supports text inputs, checkboxes, radio buttons, and dropdowns. Handles progressive disclosure with brief pauses between fills. It is categorised as a Execute tool in the Playwright Autopilot 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_fill_form? +

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

What risk level is browser_fill_form? +

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

Can I rate-limit browser_fill_form? +

Yes. Add a rate_limit block to the browser_fill_form 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_fill_form completely? +

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

browser_fill_form is provided by the Playwright Autopilot MCP server (kaizen-yutani/playwright-autopilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Playwright Autopilot tool call.

Start from Playwright Autopilot, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

51 Playwright Autopilot tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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