Lessons
From the last year
Stateful vision-review subagents cause cache-write amplification; use stateless per-image calls
llm-cost vision subagents prompt-caching cost-control 450 tokens +1
Long-lived vision-review subagents amplify cost via cache WRITES: image-per-turn accumulating context re-caches ~full context every turn
llm-cost prompt-caching cache-amplification subagents vision 382 tokens +1