Why most AI skills fail (and the two ways they fail)

Every "skill" you install for your AI is the same thing under the hood: text that gets prepended to your request. That text can do three real things — inject knowledge the model doesn't have, elicit capability the model already has, and scope how it behaves. What it cannot do is install competence that isn't in the weights. "You are a world-class CFO" adds a costume, not a CFO.

That distinction is the difference between a skill that helps and one that quietly hurts you.