When you start to writing, you'll realise you won't need to narrate every hour of a characters day. It's necessary for an ever-building plot to quicken the pace and become more relevant as you go. This means the descriptive aspect of a story decreases significantly. Characters and places for example, don't need describing more than once, and even then the initial description could be brief but still effective.
My reason for writing this chapter is because I find I almost always over-describe scenes. But if you choose the right descriptors, you don't necessarily need chunks of description alone. From reading, I've found that the books I enjoy jump straight into plot-lines. And that when I'm gripped into reading a story, I end up feeling annoyed like the description's got in the way. I understand that some books or writers might favour description to action, but over-describing characters and places Etc. and not focusing enough on a progressing plot means there's meat but no bones.
Over-description could be solved by planning what's going to happen in a chapter you are yet to write or editing parts you've written and possibly summerising what's happening/happened per chapter.
But, you shouldn't under-describe either. Enough detail should be given that the reader can visualise what you're describing but then move on to actions. Nicely written description should open a chapter, followed by plot hooks, because they're the main a reader will stay gripped.
Either way, feedback on published chapters as well as re-reading your stories should help the balance.
Do you ever find yourself over or under-describing?