As a lot of people keep pointing out over and over again, a job ad is an ad. Its often forgotten purpose is to get someone competent excited enough about your company and the job opening you're trying to fill to send in a well crafted resume with a well crafted cover email[^1].
If I read it, I want to know why I should be excited to work at your company, not that I'll be manually backing up the git server every Friday morning between 4.45am and 5.13am.
Good programmers are really hard to find - especially in the current startup boom - and you're not going to attract them by putting out job ads that look like they've been written by Catbert in one of his fouler moods.
A list of meaningless job duties like "3% of time will be spent swearing at the office Keurig" doesn't tell me anything about what it's like to work at your company and especially the team that you are currently hiring for. That's what all but the most antisocial software engineers are interested in - tell me about the team and the people who make up the team, and tell my why I want to work with them instead of where I'm working now or the myriad of other companies that are also trying to hire a developer right now.
Every software engineer knows that a list of supposed job duties is often meaningless if the organization has any flexibility because over time, the job will get tailored to the intersection of an individuals strengths and the company's needs. Tell me about that instead.
[^1] Of course you'll also get emails with no content in the mail body and a lone resume attached from people who use a scatter gun approach to job search, but we're not talking about those kind of candidates here. If you want to attract them, you don't need to put a lot of effort into the job ad.