I’m trying to do X in programming language Y, are there any libraries for that and can you give me an example”

I found them to be really bad for that in my testing. They’ll happily hallucinate the existance of a library with a vaguely plausible name, spit out ‘sample’ code for it, and then when I ask for a link to the documentation, say “I’m sorry, that library doesn’t exist”. It drives me round the bend!