Does anyone have a good recommendation for explaining or as a primer on KV cache?

If you want the actual maths instead of handwaving, I recommend: https://arxiv.org/abs/2207.09238

For something gentler, 3Blue1Brown: https://www.youtube.com/watch?v=eMlx5fFNoYc (this is part of a series)

convert this question to KV cache and give it to your agent