In your life as an office worker, you will be asked to execute a number of assignments that don’t really fall under your “job description.” This is mostly because your job description is never really made all that clear to you in the first place. It is left just nebulous enough for there to be room for interpretation.
When you perform tasks that are what you feel to be out of the realm of the ordinary, it’s usually because you’re overcompensating for a co-worker’s ineptitude or possible genius. Only the truly dumb or the truly intelligent employee can force other people like yourself to do things for them that you really shouldn’t have to.