The mapping holds, and the model-is-10%, harness-is-90% number is the part teams underweight when they pick a framework. The one that bites earliest for me is idempotency, people who'd never ship a service without idempotency keys will happily let an agent retry a non-idempotent tool call, then debug the double-executed action. If agent memory really is an event log, do you key tool-call results by an idempotency token so a retry replays instead of re-executes?