claude-code-system-prompts/system-prompts/tool-parameter-claude-in-chrome-javascript-code.md

The JavaScript code to execute. Evaluated in the page context with REPL semantics: top-level await works, and the result of the last expression is returned automatically — write the expression you want (e.g. window.myData.value, or await fetch(url).then(r=>r.json())) rather than return .... You can access and modify the DOM, call page functions, and interact with page variables.