My AI agents don't talk to each other

I run seven agents over the same domain. They have never once sent each other a message. That was not the plan. The plan was the thing everybody builds first: a coordinator that hands work between specialists, agents that call each other, a shared conversation they all append to. It worked in the demo and it fell apart the moment the work got real. What replaced it is boring and it has held up: every agent writes claims to one shared record, and nothing else. No agent reads another agent's reasoning. No agent can call another agent. The record is the only channel. Here is why, and what it cost. What breaks in the group-chat design Three things, roughly in the order they hurt. Context grows without bound. If agents converse, every agent needs everyone else's output in its window to participate. Six specialists means each one is reading five other monologues. Your token spend goes quadratic in the number of agents and the marginal agent makes the others measurably worse. Errors laminate. Agent B reads agent A's output as input. If A was confidently wrong, B does not treat it as a claim to be weighed — it treats it as context, which is to say, as true. By the time it reaches F you have a well-reasoned conclusion resting on a hallucinated premise, and nothing in the transcript flags where the floor gave way. You cannot answer "why." Six weeks later someone asks why the system concluded X. The honest answer is "there was a conversation." That is not an answer you can act on, and it is not an answer that survives an auditor. Agents as authors, not as callers The reframe that fixed it: an agent is not a function other agents invoke. An agent is an author with a domain of authority . Each of mine owns a slice of the problem and may only make claims inside it: Agent Domain Claims it may make Verification What is true about the thing today Observed facts, source records, reconciled geometry Design What it should become Plan gaps, code compliance, takeoffs Recovery What can be