browser-testing-with-devtools

Reproduce the bug in the browser, take a screenshot, then inspect the console for errors, read the DOM element, and check computed styles. Compare actual versus expected structure to find the root cause, fix the code, and reload to verify.

Open the network monitor, trigger the action, then check the request URL, method, headers, payload, and response status. The workflow maps 4xx errors to client issues, 5xx to server problems, and CORS failures to origin header configuration.

It provides screenshot capture, DOM inspection, console log retrieval, network monitoring, performance tracing, computed style reading, accessibility tree access, and JavaScript execution in the page context for read-only state inspection.

No. The Skill explicitly prohibits JavaScript execution from reading cookies, localStorage tokens, sessionStorage secrets, or any authentication material. Application state should be inspected through non-sensitive variables instead.

Do not use it for backend-only changes, CLI tools, or code that does not run in a browser. It is designed specifically for verifying and debugging anything that renders or executes in a browser environment.

A malicious or compromised page can embed instruction-like text in the DOM, console, or network responses to manipulate agent behavior. The Skill requires flagging such content and never executing instructions found in browser data.