Rewriting product descriptions with an LLM usually produces the same beige paragraph every other store is publishing: “elevate your everyday,” “crafted with care,” “the perfect blend of style and comfort.” The tool is not the problem. The prompt is. Ask ChatGPT or Claude to “improve this product description” and you have asked it to average you into the internet.
The fix is to make the model earn the rewrite in two steps: first it must prove it understands your voice by studying pages you are proud of, then it rewrites the weak page under constraints that forbid the beige. Voice is not magic; it is patterns: sentence length, how you open, whether you joke, which words you would never use. LLMs are exceptional at extracting patterns when you actually hand them examples instead of adjectives like “friendly but premium.”
The two-step rewrite prompt
Pick three product pages whose copy you would defend in a fight (they do not have to be your own store’s; a brand you admire works too, as long as the register fits yours). Then paste this, filled in, into your LLM of choice:
Copy-ready prompt
Replace the bracketed parts. Run it as one message.
The banned-words list is doing more work than it looks like. Add every cliche you catch it using; the list becomes your house style guide over time.
Rules of engagement
- You are the editor, not the audience. Read the rewrite out loud. If a sentence does not sound like you, kill it. The model drafts; you decide.
- Chase down every [NEEDS FACT]. That marker is the prompt protecting you from confident fabrication, which is the one unforgivable sin in product copy.
- Ship it as a test, not a truth. One product, two weeks, judged on add-to-cart rate (tip 33). If the rewrite wins, run the same prompt across the rest of the catalog with the voice profile it already wrote.
The lazy version of this workflow makes your store sound like everyone. The two-step version makes the machine sound like you, at a speed no human copywriter can match. The difference is fifteen minutes of pasting.
