Why agents delete or overwrite each other's work — and how to fix it

A very common complaint you'll see from people working with AI agents is: 'My agent deleted a bunch of stuff I was working on.' Almost always, this happens because multiple agents are working on different features on the *same* branch. If you tell one agent to redesign the landing page and another to make API calls faster, the second agent might look at how the landing page is calling the API, decide it's inefficient, delete those pages, and rewrite them — even though the first agent was actively working on that page's design. The agents aren't doing anything wrong; they're doing exactly what you told them. The fix is isolation: give each agent its own Git worktree so they literally cannot step on each other's work.