browser_fill · Abrasio MCP: Risk & Policy

WHAT IT DOES

What browser_fill does on Abrasio

AI agents invoke browser_fill to trigger actions in Abrasio. 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_fill needs a policy

This tool interacts with a real web browser to click and fill form fields, simulating human input. It can submit credentials, personal data, or trigger form-based actions in external systems. It combines browser actions (click) with data entry (fill), making it an Execute-category tool. Misuse could result in submitting forms, entering malicious data, or interacting with authenticated sessions — hence high severity.

From the tool's definition Click a form field and fill it with text using human-like typing

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_fill Rate-limited

browser_fill 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_fill": {
      "limits": [
        {
          "counter": "browser_fill_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 Abrasio, so you can run agents against it safely.

FAQ

Questions about browser_fill

What does the browser_fill tool do? +

Click a form field and fill it with text using human-like typing. It is categorised as a Execute tool in the Abrasio 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? +

Register the Abrasio MCP server in PolicyLayer and add a rule for browser_fill: 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 Abrasio. Nothing to install.

What risk level is browser_fill? +

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

Can I rate-limit browser_fill? +

Yes. Add a rate_limit block to the browser_fill 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 completely? +

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

browser_fill is provided by the Abrasio MCP server (scrape-technology/abrasio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.