The AI is not intelligent. Its really hard to grasp cleanly. But it can't do anything logically like we do. Its pattern matching. It has to be a pattern its seen; then it can assemble them. If there are competing patterns - it'll trip up being consistent. Long established libraries and languages that change the least, it'll be best at. Anything newer it'll be bad at - even with documentation. The only way out is to give it tests, then it can loop over several simpler problems, where the errors (failed tests) match well onto the more basic primitives that don't really change (wrong string, wrong type, wrong structure, etc)
I think I finally have a way to describe how AI works: infinite experience, none of the smarts.
1) A designer that uses Figma correctly (using well defined components / design systems) 2) A front-end framework as close to HTML / CSS as possible for the visuals (I have success with Web Components / Lit) with Figma MCP
The front-end is usually one-shot using frontier models. However in my experience, designers are all over the place with using Figma correctly.