Your “build the undo before the buy” principle is a useful test for agent commerce. I’d add a small operational layer: make every purchase produce a replayable decision record containing the user mandate, candidate options, price and policy checks, authorization scope, and final outcome. If a dispute occurs, that record lets the merchant distinguish a bad recommendation from a stale price, duplicate execution, or an agent acting outside its budget. The same record can feed automatic safeguards: pause after repeated failures, require approval when confidence or total crosses a threshold, and revoke a mandate without disabling unrelated tasks. Treating recourse as an observable workflow makes delegated spending easier to audit and improve.