First-time authors often use a lot of words in their manuscripts, which can bog down the writing and distract readers. A good editor can help reduce wordiness and hone into the action. Depending on genre and writing style, some wordiness can add to the delight of the story, but for fast-paced mystery, thriller, or sci-fi, cutting down on words will create more tension and grip the reader. Always though, there is no need to repeat or to explain the obvious. An article by C.S. Lakin shows an example of how to cut words:

How Novelists Can Say More with Less