new_page · Chrome Devtools MCP: Risk & Policy

WHAT IT DOES

What new_page does on Chrome Devtools

AI agents invoke new_page to trigger actions in Chrome Devtools. 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 new_page needs a policy

This tool executes a browser control action (page creation) that has real-world side effects—it instantiates a new browsing context. While not irreversible (pages can be closed) or destructive in data terms, it performs an active operation on an external system (Chrome), making it Execute rather than Read.

From the tool's definition Creates a new page in a Chrome browser context via DevTools API; this is an operation that triggers external browser behavior with side effects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

new_page Rate-limited

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": {
    "new_page": {
      "limits": [
        {
          "counter": "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 Chrome Devtools, so you can run agents against it safely.

FAQ

Questions about new_page

What does the new_page tool do? +

Creates a new page. It is categorised as a Execute tool in the Chrome Devtools MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on new_page? +

Register the Chrome Devtools MCP server in PolicyLayer and add a rule for 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 Chrome Devtools. Nothing to install.

What risk level is new_page? +

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

Can I rate-limit new_page? +

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

Set action: deny in the PolicyLayer policy for 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 new_page? +

new_page is provided by the Chrome Devtools MCP server (nimbus21/chrome-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.