[aartav]

I don't this the job description is the complicated puzzle - its people that are the complex puzzle.

Even with the most perfectly defined job description, you might have many candidates who "fit" that description, so you have to weigh a lot of other factors which run a huge gamut. Many, many times I've had multiple candidates that are more-or-less the same in terms of experience, technical competence, ability to learn, get shit done, etc - so you start looking at other factors and it can get down to things like communication, personal hygiene, general awkwardness, etc.