> Create a plastic enclosure sized to go under a desk, ok add a usb receptacle opening, ok add flanges with standard screw holes
With vague specifications like these, you'd get garbage from a human too.
What works for software, and I suspect for other technical fields like CAD too, is to treat it like a junior developer who has an extreme breadth of knowledge but not much depth. You will need to take care to clearly specify your requirements.
> You'll never have better input than this at the beginning of the project from the person that brings the use-case
That's as may be, but again, it's not much different to being a software developer.
Someone might ask you to create a website for their business. It's your job, as the expert, to use the available tools - including AI - to turn their requirements into working code. They might say "put a button for the shopping cart into the top right". It's then your job, as as the technical expert, to get that done. Even the laziest of devs wouldn't expect to just copy/paste that request into a AI tool and get a working result.
It takes time to learn to use these tools.
When I'm using AI to help me write code, depending on the complexity of what I'm working on, I generally write something very similar to what I'd write if I was asking other developers for help (although I can be much terser). I must specify the requirements very clearly and in technical language.
Usually I keep a basic prompt for every project that outlines the technical details, the project requirements, the tools and libraries being used, and so on. It's exactly the same information I'd need to document for another human working on the project (or for myself a year later) so there's no wasted work.
> With vague specifications like these, you'd get garbage from a human too.
You'll never have better input than this at the beginning of any project from the person that brings the use-case. That's a full job to help them define the needs more accurately. And if you always work with clear specifications it's just because there's someone in front of you that has helped write the spec starting from the loose business requirement.
> You will need to take care to clearly specify your requirements
Yes, but as I discussed above, for such tasks it's going to be very frustrating and less efficient than doing things by yourself. The only reason why you'd accept to go through this kind of effort for an intern is that because you expect him to learn and become autonomous at some point. With current tech, an LLM will forever remain as clueless as it started.