browser_new_page · Browser MCP: Risk & Policy

WHAT IT DOES

What browser_new_page does on Browser

AI agents invoke browser_new_page to trigger actions in Browser. 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_new_page needs a policy

Opening a new browser page is an executable action that modifies browser state and can trigger side effects (loading pages, executing JavaScript, tracking cookies, etc.).

From the tool's definition Tool performs browser automation action 'Open a new browser page (tab)' - a programmatic operation that triggers external state changes in the browser environment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_new_page Rate-limited

browser_new_page 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_new_page": {
      "limits": [
        {
          "counter": "browser_new_page_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 Browser, so you can run agents against it safely.

FAQ

Questions about browser_new_page

What does the browser_new_page tool do? +

Open a new browser page (tab) (see browser_docs). It is categorised as a Execute tool in the Browser 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_new_page? +

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

What risk level is browser_new_page? +

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

Can I rate-limit browser_new_page? +

Yes. Add a rate_limit block to the browser_new_page 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_new_page completely? +

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

browser_new_page is provided by the Browser MCP server (ricardodeazambuja/browser-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.