5.3 — Error Propagation in Multi-Agent Systems

CCAR-F Domain 5 · Task 5.3

What You Need to Know

Structured Error Context (4 elements)

1. Failure type (transient / validation / business / permission)
2. What was attempted (query, parameters, target)
3. Partial results gathered before failure
4. Potential alternative approaches

Two Anti-Patterns

1. Silent suppression — return empty results marked as success (worst; invisible gaps)
2. Workflow termination — kill entire pipeline on one failure (wastes completed work)

Middle ground: structured error propagation → coordinator decides recovery.

Access Failure vs Valid Empty Result

	Access failure	Valid empty result
Meaning	Tool never reached data	Query ran, found nothing
Retry?	Consider yes	No — this IS the answer

Coverage Annotations

Synthesis output should note which topics are well-supported and which have gaps due to unavailable sources.

Local Recovery

Subagents recover locally from transient failures before propagating. Only escalate persistent failures with structured context.

Key Concept: Structured error context enables intelligent coordinator recovery. Avoid silent suppression and workflow termination.

Exam Traps

• Catching timeout and returning empty results as success
• Terminating entire pipeline on one subagent timeout
• Returning generic "search unavailable" status
• Retrying a valid empty result