Observability for multi-agent systems: instrumenting for split-brain, goal drift, and context drift

Every coordination failure in a multi-agent system is a diff between two agents — and per-agent monitoring cannot express a diff. You can have complete, exception-free telemetry on every agent in a crew and still be structurally blind to split-brain, goal drift, and context drift, because each one lives in the comparison your telemetry has no join key for. What to actually instrument for each of the three, which probes are free and which cost a model call, and how to sample a crew for belief reconciliation without paying O(n) extra calls at every checkpoint.

October 16, 2026 · 10 min · 1939 words · Loop & Retry