Writers love to describe the worlds they inhabit, or the worlds they are creating. It might be the original writerly impulse we felt as children; it's also so satisfying because it's a way of showing off our imaginations and our skills, proving that we have created a fully-realized universe, or that our observational skills are particularly sharp. While description might be the writer's favorite part of a story, however, it's often not a reader's. If the action of a story is engaging, then a reader will hurry on through any slow, meandering description, or even skip it outright, wanting to get the action going. Striking that balance between description and action is an important skill for any writer to learn.
1. Is that passage for the story, or for you?
As I wrote, description can be one of the more fraught areas of a story, simply because we're unable to see it objectively. Description is a writer's chance to shine; it's the place where we can show off our vocabulary, our astute observations, our sheer cleverness. That's why writers love description, and readers only sometimes love it. Above all, you're writing a story, not a description of a place or a world; so when you've written a page of just how a hotel lobby looks, or the color of the water in a particular stream, stop and ask yourself the question above. Are you writing this just to show off, or for your own pleasure, or does the story really need it?
2. Is there too much action without orientation?
All this is not to say that description is unnecessary. Description orients the reader in the world, and makes her feel she knows where she is and what the world looks like. It also makes the reader inhabit the world, by letting her experience all the sensory details of the world. And finally, description is about earning the reader's trust. Particularly well-written description will convince the reader that she's in good hands, and that this is going to be a good book.
So are you hurrying forward in the action while neglecting this crucial orientation? Maybe you're galloping ahead with action out of a sense of insecurity, wanting to keep your reader constantly entertained, afraid that she'll close the book any minute. So why bother telling your reader that it's raining, or that the characters are currently on a Scottish moor, right? No time for that boring stuff ,Aei we've got to solve another murder!
The problem with this philosophy is that it doesn't allow the reader to participate in your story, or to feel like she belongs in your world. We read to experience; but we can't experience without description.