https://shadycharacters.co.uk/2023/01/miscellany-98-a-novelistic-conundrum/#comment-573927
On precis, summaries, chapter TOCs, abstracts, synopses, nutshells, etc: I remember them being called “precis” by a prof of mine, and they are referred to that way in the LaTeX typesetting world, though I don’t know why. I prefer “nutshell” simply because it can be referred to as “the nut” in various ways.