close_browser · Chromium ARM64 Browser MCP: Risk & Policy

WHAT IT DOES

What close_browser does on Chromium ARM64 Browser

AI agents use close_browser to create or update resources in Chromium ARM64 Browser — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Chromium ARM64 Browser environment.

WHY IT NEEDS A POLICY

Why close_browser needs a policy

An AI agent can call close_browser faster than any human can review — one bad instruction and it creates or modifies resources in Chromium ARM64 Browser by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

close_browser Rate-limited

close_browser stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "close_browser": {
      "limits": [
        {
          "counter": "close_browser_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Chromium ARM64 Browser, so you can run agents against it safely.

FAQ

Questions about close_browser

What does the close_browser tool do? +

Close the browser instance. It is categorised as a Write tool in the Chromium ARM64 Browser MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on close_browser? +

Register the Chromium ARM64 Browser MCP server in PolicyLayer and add a rule for close_browser: 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 Chromium ARM64 Browser. Nothing to install.

What risk level is close_browser? +

close_browser is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit close_browser? +

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

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

close_browser is provided by the Chromium ARM64 Browser MCP server (nfodor/mcp-chromium-arm64). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.