Why Half of This Week's Trending GitHub AI Tools Are Called "Skills"

I went through this week's 20 trending open-source GitHub AI tools and repos expecting the usual mix: a new database, a flashy CLI, maybe a UI library with great screenshots. What I got was something stranger. Four separate repositories in the top 20 have "skills" in their name. Agent Skills. Flutter Agent Skills. Garden Skills. Skills for Real Engineers. Different authors, different teams, different use cases - but all of them attempting to solve the same underlying problem: how do you make AI