I used to like designing skill pages that looked cool and seemed useful. But this time, after removing all the skill webpage layers, I saw its true essence: it's not the homepage, not the local server, and not the web entry point, but the functionality of the skill itself.

If a system can still run without a webpage, it means you're preserving the capability; if it collapses as soon as you remove the presentation layer, it indicates you're mostly maintaining a shell that looks complete.
When working on AI workflows, you should prioritize preserving the capability first and the presentation later.
Only those that can shed their shells without dying are truly core.