Hierarchical failure mode — decomposition drift cascades
happy path
top manager
splits: eng + legal
eng-manager
fe + be
legal-manager
lawyer
React + API issues
legal non-compliance
top synthesis
covers user question
perturbed path
top manager
splits: eng + FINANCE (!)
eng-manager
fe + be
finance-manager
obeys mistaken label
React + API issues
$42k/mo over budget
top synthesis
LEGAL QUESTION UNANSWERED
guardrails
cap tree depth at 2 · bounded reconciliation rounds · canary worker at each level · decomposition-drift alerts
CrewAI Process.hierarchical and nested LangGraph supervisors both inherit this failure surface