If you're working from OpenAPI, ideally you want to be able to process any, potentially full of shit formatting spec file. I find that half the integrations I run into have some old weird version of Swagger, and the rest work like hell to stay up to date with the 3.x spec track.

I agree, I wish, it will be a solved problem eventually. Just feeding a complex data model like that to the paper shredder that is the LLM, for making decisions about whether DELETE or POST is used is just asking for trouble.