The world's greatest copywriters have the gift of writing as if they are speaking to a close friend in an intimate conversation. They develop a bond with the reader, and can make their case from a position of credibility rather than as a carnival barker.
Long, descriptive copy in your ad takes up more space than quick little bullet points. But you'd probably rather have a higher quality customer rather than a price-gouger. Start by writing a friendly conversation you might have with an old friend about your products and services.
Trim the conversation down so that it fits and can be read easily, but make it friendly, and you're more likely to find a friend.