This is a proper content design system for n8n, the workflow automation tool. It's opinionated in all the right ways: sentence case everywhere, active voice, contractions encouraged, no Latin abbreviations. The guidelines are specific enough to actually use (complete i18n key naming conventions, a table of where copy lives in the codebase, three working modes for write/review/audit). What I like is it pushes back on the usual content design platitudes and gets tactical about the difference between onboarding copy and error states, when warmth earns its place versus when clarity is the only job. If you're writing UI copy for a technical product and tired of voice and tone docs that don't actually help you decide between "Save" and "Save changes", this gives you a framework.
npx skills add https://github.com/n8n-io/n8n --skill content-design