Agent-to-Agent Communication Protocols: The Interface Contracts That Make Multi-Agent Systems Debuggable
When a multi-agent pipeline starts producing garbage outputs, the instinct is to blame the model. Bad reasoning, wrong context, hallucination. But in practice, a large fraction of multi-agent failures trace back to something far more boring: agents that can't reliably communicate with each other. Malformed JSON that passes syntax validation but fails semantic parsing. An orchestrator that sends a task with status "partial" that the downstream agent interprets as completion. A retry that fires an operation twice because there's no idempotency key.
These aren't model failures. They're interface failures. And they're harder to debug than model failures because nothing in your logs will tell you the serialization contract broke.
