Compare agent skills before installing.

Creates or modifies domain types in src/domain/ — value objects, discriminant unions, and aggregate roots. Use when adding a new domain concept, defining invariants for an existing type, or placing a shared discriminant union that is used across multiple use-cases. Do NOT use for orchestrating I/O or business logic — use `use-case` instead. Do NOT use for infrastructure concerns — use `adapter` instead.

When the user wants to write, rewrite, or improve marketing copy for any page — including homepage, landing pages, pricing pages, feature pages, about pages, or product pages. Also use when the user says "write copy for," "improve this copy," "rewrite this page," "marketing copy," "headline help," "CTA copy," "value proposition," "tagline," "subheadline," "hero section copy," "above the fold," "this copy is weak," "make this more compelling," or "help me describe my product." Use this whenever someone is working on website text that needs to persuade or convert. For email copy, see emails. For popup copy, see popups. For editing existing copy, see copy-editing. For the offer underneath the copy (bonuses, guarantees, value framing), see offers.