Multi-Agent Failure Modes — Detail & Examples

Part of Context Management · overview: domain-5.html

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A full four-part structured error report, the two anti-patterns compared side by side, and where retries belong (subagent) versus strategy decisions (coordinator).

5.2aThe four-part error context

WORKED EXAMPLE · A SUBAGENT REPORTING A FAILURE WELL

SCENARIOA research subagent was asked to pull recent case studies from an academic database and hit a snag partway through.

Failure type: transient — the database returned a rate-limit error, not a permanent rejection.
What was attempted: "Searched the academic database for 'renewable energy policy 2024-2026', page 2 of results."
Partial results: 3 of 5 targeted sources were already retrieved successfully before the rate limit hit.
Alternatives: retry after a short delay, or proceed with the 3 sources already gathered and flag the gap.

Why this matters:The coordinator can now decide intelligently — wait and retry, or move forward with partial results — instead of just knowing "something failed."

5.2bThe two anti-patterns, side by side

Which is worse, and why

Silent suppression: the coordinator treats an empty/failed result as a valid "nothing found" answer. This is the worse of the two — it prevents any recovery from ever being attempted, because the coordinator doesn't even know there's a problem.
Workflow termination: one subagent's failure kills the entire pipeline, discarding perfectly good partial results other subagents already produced. Wasteful, but at least visible — someone notices the whole thing stopped.
The fix for both is the same structured error context above: it makes a real failure visibly different from a real empty answer, and lets the coordinator target just the failed piece instead of discarding everything.

5.2cWhere retries belong

SUBAGENT (local retry)Timeout on first attempt → retries automatically once with backoff → succeeds. Coordinator never even sees this happen.

COORDINATOR (strategy-level)Subagent reports a permission failure (access denied) — this can't be fixed by retrying, so the coordinator escalates for a human to grant access, or picks a different data source entirely.

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Claude Certified Architect — Study NotesDWG 5.2