browser_select · LocalAnt MCP: Risk & Policy

WHAT IT DOES

What browser_select does on LocalAnt

AI agents invoke browser_select to trigger actions in LocalAnt. 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_select needs a policy

This tool performs a browser automation action (selecting a form element option), which constitutes executing an external operation in a live browser environment. It can trigger form submissions, page navigation, or other side effects depending on the target application. Classified as Execute rather than Write because it drives browser UI behavior rather than directly modifying stored data.

From the tool's definition Select an option in a <select> by selector + value — triggers a browser interaction/UI action

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_select Rate-limited

browser_select 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_select": {
      "limits": [
        {
          "counter": "browser_select_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 LocalAnt, so you can run agents against it safely.

FAQ

Questions about browser_select

What does the browser_select tool do? +

Select an option in a <select> by selector + value. It is categorised as a Execute tool in the LocalAnt 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_select? +

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

What risk level is browser_select? +

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

Can I rate-limit browser_select? +

Yes. Add a rate_limit block to the browser_select 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_select completely? +

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

browser_select is provided by the LocalAnt MCP server (yuga-hashimoto/localant). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.