Prompt-Caching | Sebastian Spicker

2026

1 article

25 Aug 2026 Token Saving, Revisited: Right About the Noise, Wrong About the Bill In June I argued that token saving in agent systems is noise reduction. The quality half of that argument holds, and the evidence for it is stronger than the June post showed. The cost half rested on an assumption I never wrote down: that fewer tokens always means a smaller bill. With prompt caching, a token you keep is far cheaper than a token you change, so some compression costs more than it saves. And the filters I recommended put their own tool definitions into every request. This post does the arithmetic. llmagentscontext-management