I think it could potentially be useful. Sometimes I need "simple" shapes that still are somewhat annoying to create. And I think you don't need to one-shot these, the process is permitted to be iterative! The skills can be improved by time by revising AGENTS.md, e.g. "when I say L-bracket, I probably mean..".

I think going from a picture to an initial starting point with well-"thought"-out structure for CAD purposes could potentially be very useful. Optimally you could just enter the measurements and be done.

Oh, that's a bit misleading then when the prompt on the main page is "Create a centered 100 x 60 x 20 mm block with four 8 mm vertical through-holes. Add only a 2 mm chamfer on the top outer perimeter"

Looking at the L-bracket one, the specification is actually instructing the gussets to overlap the holes, so it actually performed both better and worse than I expected

And yes, as someone who CADs mechanical parts a reasonable amount, you have to be very precise, hence me wondering how the given prompt could be useful