You can tell a 'visa job advert' by the fact that it asks you to 'reference case
NNN when replying', as well as the highly-specific description of required skills and experience.
At least, you could when this was all conducted with adverts in newspapers. But why would someone engage a headhunter to fill a position they didn't really want to fill? Is that now a necessary part of the pretense?
I believe the hiring company has to provide evidence (to the government) as to why none of the applicants were suitable so everyone who applies results in documentation work for someone