What it is — An experiment-backed essay arguing that a component library and token set aren't a design system if they don't also carry forward shared decisions about how the product should behave.

Key points

• Three AI agents given the identical library (shadcn/ui on Base UI), token layer, and app shell each built a different settings page — some behind tabs, some as cards, some as long forms — despite passing the same token linter.
• The failure wasn't in the components; it was in composition — nobody had made a canonical decision about what a settings page is, so each agent answered the question separately.
• The real missing work of a design system is choosing an answer, making it canonical, and putting it where the next builder (human or agent) will find it.