Skills are _like_ prompts, yes, they're extra info added to the context. A prompt is just a prompt though, an agent like Claude could use multiple skills in one go, which seems impossible to do with Zerostack.
Skills are not just prompts.. the entire problem that skills solve is runtime discoverability via a skill description. Agents can self-recognize that a skill would be useful in a situation, and then load+use.
Prompts are just text templates entered by the user, and the user must specifically know when to and remember to invoke them. If you’re just using skills as if they are the same as prompts, you’re totally missing out on the entire benefit that skills provide!