Key points
- Structured error context: failure type, attempted query, partial results, alternative approaches.
- An access failure (timeout, service down) needs a retry decision; a valid empty result is a successful query with no matches.
- Generic statuses such as "unavailable" hide everything the coordinator needs.
- Two anti-patterns: suppressing errors by returning empty results as success, and terminating the whole workflow on a single failure.
- Subagents recover locally from transient failures and propagate only what they cannot resolve, with attempts and partials attached.
- Synthesis output carries coverage annotations: which findings are well supported and which topics have gaps because sources were unavailable.
Common misconceptions
- "An empty list is the safe way to report a failure." It is the most dangerous: the gap disappears.
- "One failure should abort the run so nothing wrong ships." A partial result with a noted gap is usually the better outcome.
- "The coordinator will retry anyway, so a generic status is fine." It cannot retry well without knowing what failed.
Watch for
Options that route every blip to the coordinator (latency), hand every failure to a human (cost), or finish the run with a clean-looking but incomplete report (safety). The best answer keeps the information flowing and the decision with the coordinator.
Practice Task 5.3
Start with the free 10-question check to see where you stand across all five domains. In CCA Prep Studio, 56 practice items cover this task, each tracked toward your mastery score.