close_page
Closes the page by its index. The last open page cannot be closed.
This record as markdown: /tools/async23-chrome-devtools-mcp/close-page.md
What close_page does on Chrome Devtools
AI agents call close_page to permanently remove resources in Chrome Devtools, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why close_page is rated Critical
Closing a browser page is irreversible — any unsaved state, form data, or in-progress work on that page is permanently lost. This is a destructive action that cannot be undone, warranting the Destructive category. Severity is medium because the blast radius is limited to a single browser session/page rather than persistent data storage.
From the tool's definition Closes the page by its index. The last open page cannot be closed.
Attacks that exploit this kind of access
The rule that runs close_page safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Chrome Devtools, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For close_page, this is the rule to start with:
close_page is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Chrome Devtools, apply this rule, and every close_page call is checked against it from then on.
Questions about close_page
Closes the page by its index. The last open page cannot be closed. It is categorised as a Destructive tool in the Chrome Devtools MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Chrome Devtools MCP server in PolicyLayer and add a rule for close_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.
close_page is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the close_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.
Set action: deny in the PolicyLayer policy for close_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.
close_page is provided by the Chrome Devtools MCP server (@async23/chrome-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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