The agent skills spec does not define any "type" field, so as a user I am very confused by the tool asking me if my skill is a "workflow" or "utility" or "analysis" skill because the actual effect of this choice (if any) is not described anywhere.

I suggest a general principle that the app needs to provide hints (or links to docs) when referencing nonstandard options like this. For example:

Type of skill (aka.ms/skill-types):
   > workflow
     utility
     analysis

or

Type of skill:
   > workflow        Interacts with factory equipment for industrial workflows
     utility         Optimized for interacting with your local electricity provider
     analysis        Enables statistical tools and analysis techniques for the agent