To be clear: most job descriptions suck. They are standardized, boilerplate, Corporate Speak documents that rarely describe the actual work to do on the job.
But job descriptions are often all we have to help us figure out what the job is about and how we relate to the job. How should we use the job description to help prepare for your interview questions?
Remember, all interview questions have three answers: I can do the job, I want to do the job, and I can fit in with my manager and team. Just those three.
The motivation for wanting the job comes from you, but the job description can help us determine the job skills the hiring manager is looking to acquire and some clues for fitting in with the team.
For each of the job skills, pull from your work performance an example of how your work demonstrated the job skill. The best answers are ones contained in powerful interview stories that show your work, how you overcame obstacles and produced verifiable results to the department or business.
You probably won't have every job skill listed; especially true today where every employer wants a PhD in thinking and experience in every job on the planet for an entry level position... But this fact also gives you clues to the work. The list of job skills tells you how complicated the job is -- or if having every job skill represented means the manager has no clear direction for how to do the work. Honing your interview questions of the manager in this area is needed.
If you don't have every job skill on the job description and you get the interview, you'll need to determine from your interview questions how important the skill is to have for your success. Or determine how to get the job skill so you can add it to your portfolio.
The job description usually includes information about the company, department, or team environment. Don't you love all the "work in a fast-paced environment" requirements out there?
In preparing answers to interview questions about how you would fit in with the group, this company, department and team environment information is where you start.
You have two tasks here. First, you need to prepare answers to how your work and personality fit into the environments described. How do you work in a fast-paced environment? How do you tell that to a hiring manager?
Secondly, if the environment sounds like standard, Corporate Speak "plays well in the sandbox" talk, you'll have to develop some interview questions of your own to ensure the corporate culture will fit your best way of completing your work. If you want heads-down time to complete tasks and the corporate culture is all about 1000 meetings a day, your chances of success in the new job diminish. If the job description sounds bland, you'll need to ask.
And, of course, you've already figured out the best working environment for you...right?
Preparing for the interview by consciously going through the job description won't give you all the answers since so many job descriptions are poor representations of the job. But you'll be far ahead of your competitors by preparing to answer interview questions from the job description.