Claude is now instructed to close browser tabs it opened once they're no longer needed, unless you want them kept open
What
Tool instructions for browser tools now tell Claude that tabs it opens itself — whether implicitly via a standalone navigate call or explicitly for a task — are its own responsibility to close with tabs_close_mcp once no longer needed, the same as tabs created with tabs_create_mcp. This applies unless the user has asked for the tab to be kept open.
Why This keeps the browser from accumulating tabs that Claude opened and forgot about, closing them automatically instead of leaving cleanup to the user.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
4. In your `navigate` handler, accept the history keywords `"back"`, `"forward"`, and `"reload"`, treat a URL without a scheme as `https://`, then parse the URL and refuse any scheme other than `http` or `https` (`javascript:`, `file:`, `d…agents-and-tools/tool-use/browser-use-tool see the edit
Localhost addresses open directly, exactly like the default port address. This includes `localhost`, any `*.localhost` subdomain, `127.0.0.1`, and `::1`. For security, a localhost `url` must be your server's origin alone, with no path or q…desktop see the edit
Anthropic's documentation has since written up navigate, on Desktop application.