select_page · Chrome Devtools MCP: Risk & Policy

WHAT IT DOES

What select_page does on Chrome Devtools

AI agents invoke select_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 select_page needs a policy

Selecting a page changes the execution context for all future browser automation actions. While it doesn't directly read or write data, it is a stateful operation that redirects subsequent Execute-category actions (click, evaluate_script, fill, etc.) to a different target. This makes it an execution-context manipulation tool with medium severity, as misuse could redirect agent actions to unintended pages.

From the tool's definition 'Select a page as a context for future tool calls' — switches the active browser page/tab that subsequent tool calls will operate on

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

select_page Rate-limited

select_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": {
    "select_page": {
      "limits": [
        {
          "counter": "select_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 select_page

What does the select_page tool do? +

Select a page as a context for future tool calls. 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 select_page? +

Register the Chrome Devtools MCP server in PolicyLayer and add a rule for select_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 select_page? +

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

Can I rate-limit select_page? +

Yes. Add a rate_limit block to the select_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 select_page completely? +

Set action: deny in the PolicyLayer policy for select_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 select_page? +

select_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.