If you wrote 500 words to describe a "mage appearing", you need to use less description. Have a very avid description isn't a bad thing, but you CAN have too much. Once you get to the point where it's just annoying to read because just one small scene is overly descriptive, it isn't worth it. If there is one thing I learned from the bronycon fan fiction panel, it's "show and tell". Try to SHOW what's happening, not tell.