I have a big pet peeve; it's when companies boast of their benefits over their culture or their employees. I think that in any job listing, after the actual description of the job itself, a description of the team that the individual will be working on, then a description of the company, and then a description of all benefits or perks should follow. The reason I say this is because, in my idealistic mind, the company and team should compel the person to want to work there more than the benefits or, shall we say it, perks do.
Right up there with my qualms about listing perks directly under a job description is something that may surprise you: unlimited vacation. Most people would see a job listing that says "unlimited vacation" and be clicking the "Apply" button faster than their LinkedIn can oAuth them in. I see a job listing that says "unlimited vacation" and I try to quantify how many days off, on average, the company actually takes as a whole: probably not many.
The fact is that people that work at start-ups, the only companies that I have seen listing themselves as offering unlimited vacation, are competitive. They want to be the best that they can be, are constantly striving to do more, better, more efficiently. There is a reason why impostor syndrome is something that I didn't know existed until I entered the tech world. It's not a bad thing, inherently, but what that natural competitiveness can lend itself to is not taking care of ourselves. It can lead to inbox guilt; a strange version of FOMO that isn't really positive but isn't exactly perceived as negative either. Or, perhaps, not taking a day off even though you are sick, because you know that there are things that need to be done. Maybe it even presents itself in not taking as many days of vacation off for the holidays because no one else on your team is--everyone is going to be working from home, or ski lodge, or parents' house. I speak from several Christmas' worth of experience.
Unlimited vacation is a problem, especially in an increasingly remote culture, because it doesn't mandate how many days off people should take. Nobody wants to be the guy that takes too many days of vacation, and nobody really minds being the guy that's perceived as "working hard." By stating that all employees get to take two weeks of vacation or four weeks of vacation (or however many weeks off), you are letting them know that it's okay. That everyone will be taking that much time off, or, if not, they'll have that time roll over into the next year. Without that, there are no lines in the sand, and people will work themselves tirelessly without those confines of "good" and "bad" to try to fit into.
If you want to offer unlimited vacation (which I think is still a very generous offer, despite my above arguments), give a mandate of the minimum amount of time off a year. This gives your employees the "okay" to take the time, because they know that everyone else will too. The balance not only helps your employees be happy and healthy, but it will improve their productivity at work and relationships with their coworkers. Having one less thing to compare yourself to others about, especially something as crucial as vacation, is definitely one of the best perks you can give.