On one build I found 127 places bound to a raw colour instead of a named role. Every single one had passed visual review. They all surfaced the moment someone asked for dark mode.
That number is the whole argument. Not because 127 is large, but because none of them looked wrong. A value that was typed in and a value that came from the system are visually identical. The difference only exists in what happens next.
The failure isn't that the agent breaks the rules
It's that it extends them.
Give an agent a design system and ask it to build. When it reaches something the system covers, it uses the system — genuinely, reliably. When it reaches something the system doesn't cover, it does not stop and ask. It invents. And what it invents is a name that sounds exactly like one of yours, sitting right next to the real ones, reading as though someone chose it on purpose.
