LLM Tool Result Caching in Production: Reducing Agent External Call Costs with Idempotency Keys, TTL, and Invalidation Strategies
A practical guide to caching external tool results for LLM agents, covering idempotent key design, TTL semantics, event-driven invalidation, state isolation, audit replay, and a pre-launch checklist to reduce API costs and latency while avoiding cache pollution and cross-tenant leaks.