You periodically pay a fee that gives you the right to use a licensed markdown file, in the same way you can rent movies or fonts.

When you stop paying but keep using the skill, that’s called pirating.

It could be added to context only on the inference server, with the model heavily instructed not to repeat its contents. Not foolproof, obviously.

depending on what the skill does, it can be a whole collection of python/other code files, resource files (i.e., js libs, css/html templates) and markdown files with orchestration instructions