Part 2 of 2. Part 1 covered statelessness; here I tackle caching. Part 1 was about statelessness, now shipped in the 2026-07-28 spec. This time it's another feature from that same spec: caching (SEP-2549, "TTL for List Results") . It adds two tiny fields — ttlMs and cacheScope — to cacheable results, giving clients a way to avoid re-fetching the same discovery data. So I built a server that emits them, pointed real AI clients at it, and watched what actually happened. The result surpr...