Use when you need to generate, expand, or validate architecture documentation (C4, service catalog/specs, security architecture, threat model, operations model, contracts) from an established baseline. Triggers: "arch docs", "architecture docs", "C4 component", "service catalog", "service spec", "threat model", "security architecture", "operations model", "runbook", "contract spec", "Well-Architected mapping", "arch-docs gate", "validate_docs.py". Requires baseline gate PASS and fails closed if required policy inputs or docs/architecture/ are missing.