◇ Could this help me?
Yes, and this is the clearest explanation of the mechanism in this batch. Two things in it are genuinely important and widely missed. The first is that the short description is read before the body, which means a skill that never triggers usually has a description problem rather than a content problem. The second is the argument for scripts: the parts of a task that must come out identical every time should be code the model calls, not instructions the model follows, and that distinction is the difference between a skill that works reliably and one that mostly works. General practice for anyone authoring skills, and the closing point that folders and files are all you need is a useful corrective to the idea that any of this requires special infrastructure.
Help me write a skill properly rather than as a long prompt in a folder. First, for the task I describe below, split it into the parts that must produce identical output every time and the parts that genuinely need judgment. Write the deterministic parts as a script the skill calls, and keep only the judgment parts as instructions in the skill body. Then write the short description at the top as carefully as the rest, since that is what decides whether the skill ever gets used, and tell me what requests it would and would not match. Finally, show me how to test that the skill triggers when it should and that the script produces the same result on repeated runs.