What it is
Anthropic’s own skills: generate and edit Office documents (Word, PowerPoint, Excel) and PDFs from inside Claude Code, plus meta-skills for building MCP servers and authoring new skills. The canonical example of the format.
How it was vetted
Read the repo at commit 9d2f1ae (2026-07-01) and ran the injection audit
(scripts/injection-audit.mjs).
- Modest, predictable cost. 17 skills, about 1,629 always-on tokens (~96 each). Only the descriptions are standing context; the machinery loads when a skill fires.
- One heavy description, justified.
xlsxis the largest at 238 tokens. It covers a lot of spreadsheet surface, so the length buys real trigger precision. - First-party, and it shows. Scoping is clean across the board. This is the pack to read if you want to learn how skills are supposed to be written.
