Google Ads allows four descriptions of 90 characters each and typically shows one or two. Each slot should do a different job: expand the primary benefit, handle the top objection, state the offer or proof, and give the next step. Four rephrasings of the same benefit is the most common failure in generated descriptions. Use the second person, prefer numbers to adjectives, front-load the point because the tail may be truncated on mobile, mention the keyword once across the set, and match the landing page wording literally.