Scope Creep

What is Scope Creep

Scope creep is an agent quietly expanding a task beyond what was actually asked, touching unrelated files, adding a feature nobody requested, refactoring code that had nothing to do with the original task. It rarely starts as one dramatic decision, more often it is one small unrequested change that seems reasonable in isolation, followed by another.

The real cost is not the extra work itself, it is what it does to review. A diff scoped exactly to the request is fast to check: does this match what was asked. A diff that also touches unrelated files for reasons the agent decided on its own forces a reviewer to evaluate a much larger, much less predictable surface, and to trust judgment calls nobody actually signed off on.

Catching it depends on treating diff review as a real check against the original task, not just a check for obvious bugs. A reviewer asking specifically whether every changed file traces back to what was requested catches scope creep that a purely functional read of the diff would miss entirely, since scope-crept code often works fine, it just was not asked for.