Copy.ai is purpose-built for exactly this kind of e-commerce copywriting task, offering dedicated product description templates that let you generate polished, conversion-focused copy in seconds by entering a few product details. It handles tone, SEO keywords, and length variations out of the box, making it fast to work through a large catalog. Jasper is a strong alternative if you want more brand voice controls and a richer template library. Claude Sonnet works well when you need more creative or nuanced descriptions and prefer a conversational back-and-forth to refine the output. Gemini Flash is worth considering if budget is a priority, since it is free and handles straightforward product copy reliably.