Cuts your token usage by about 75% by making Claude talk like a technically accurate caveman. Drop articles, filler words, hedging, keep all the substance. It has six intensity levels from lite (just removes fluff) to ultra (heavy abbreviation) to wenyan modes that use classical Chinese compression. Stays on across the entire conversation until you explicitly turn it off. Auto-reverts to normal for security warnings or when compression would create actual ambiguity. Honestly pretty clever if you're paying per token or just hate verbosity, though the wenyan modes feel like they're showing off more than solving a problem most people have.
npx skills add https://github.com/juliusbrussee/caveman --skill caveman-cn