I Stopped Writing Better Prompts and Started Counting What My Skills Couple To

Prompts rot. Captured failures compound. Most of the AI skills you are building are mostly prompt, which is why most of them will not survive the year. Not because the prompts are bad. A skill's value is maybe twenty percent instruction and eighty percent scar tissue, and only that second part lasts. The instruction rots the moment the thing it describes moves. Encode how your team deploys and it works until the pipeline changes. Then you are debugging a prompt at 2am, with less to go on than if you had written the script yourself. So before you build another one, stop asking whether the prompt is good. Ask what the skill is holding onto, and whether that thing sits still. A skill rots at the speed of what it touches A skill rots in proportion to how tightly it is coupled to things that move. Generic scaffolding leans on stable ground like a language or a convention, so it ages slowly. Domain logic wired to a codebase that gets refactored every quarter ages fast, no matter how good the prompt is. The difference is the dependency count. "Write a unit test in this style" depends on a language and a convention. Both barely move. It keeps working for years because nothing under it shifts. Real company-specific procedure is the opposite. File layouts. Service contracts. The one edge case in the billing flow. Each detail you pack in is a thread tied to something that gets refactored. Pack in enough of them and the skill is not a tool anymore. It is a liability with good intentions, and it fails silently, because a stale prompt does not throw. It quietly does the wrong thing. That is what the skill-library pitch gets backwards. Volume is not value. A hundred skills wired to a moving codebase is a hundred things to maintain. The only part that compounds is the scar One part of a skill does not rot. The captured failure. The five-line check you added after a model confidently reported a 41 percent dividend yield. The retry that refuses to fire twice so a flaky webhook cannot