This is exactly the kind of thing I hope LLM chatbots will be genuinely useful for. Though, how often do you find it completely hallucinating endpoints / parameters etc. ?
ChatGPT hallucinates SVG path attributes. Ask it to make an svg of a unicorn - it will give you markup that looks okay, but if you look at the values of the paths, it's clearly gibberish.
(SVG is a particularly interesting case because it's XML on the outside, but several attributes are highly structured, esp g.transform and path.d. Path.d is basically the string of a Logo-like programming language. I was specifically looking at these attributes for realism, and didn't find it.)
I don't know whether that is because that is a common way of doing things or whether a previous prompt responded with a bearer token... But it wasn't right.
For me, it's a leaping off point that often saves time if I ask the right question. To your point, you have to be quick to know enough about the API to deduce whether you and Chat GPT are in the same universe.