Why AI coding agents overwrite each other—and a safer Git workflow

Two agents can understand their instructions and still overwrite each other if both write into the same checkout. The Git index, uncommitted files and local configuration are shared state. A more detailed prompt does not separate those files.

Start by giving each task a clear scope: the files it can change, what result it should produce, and how you will check it. Smaller scopes also keep the token context focused on the work that matters.

Create a branch and worktree for the task, then run the agent from that directory. Keep another task in a different worktree. Review each diff on its own before combining the branches.

Before merging, check for changes outside the requested scope and run the relevant tests. For a production change, review the final behavior as well as whether the code compiles. A separate worktree prevents file sharing; it does not prove that the change is correct.

Worktrees still share the repository history, and the branches can conflict when you merge them. They may also share databases, ports and external accounts. Use separate test resources where the task requires them.

After merging, remove the worktree and temporary branch when they are no longer needed. If the work is unfinished, preserve it first. The useful habit is a repeatable review cycle, not a larger collection of agent roles.