Code editor
Also called Text editor, Editor, IDE, VS Code
A program for opening and changing plain text files, made for code. It colours the text so the structure stands out, shows the project's folders down one side, and marks some mistakes as you type. VS Code is a common one.
You need somewhere to read what an agent wrote that isn't the agent's own account of it. Open the file it says it changed and you are looking at the thing itself, in the same folders it is working in.
Say it to your agent
“List every file you changed as a path I can open in my editor. Don't reformat anything you weren't asked to change, so that I can see the real edit.”