A product description is not decoration under a photo. It is the part of the page doing the work a shop assistant would do in person: answering the questions a shopper has before they feel safe clicking buy. When the description does that job, fewer people leave to search elsewhere and fewer returns come back marked not as expected.
Answering the unspoken questions
Every shopper arrives with questions they rarely type out. Will it fit? What is it made of? How big is it next to something I own? How do I clean it? Will it work with what I already have? A good description anticipates these in the order a shopper thinks of them.
Reducing doubt
Doubt is the gap between what the photo shows and what the shopper needs to know. Descriptions close it with specifics: exact dimensions, weight, materials, what is included in the box and what is not. Vague reassurance such as premium quality does nothing here; a precise detail does.
Supporting the brand and the search engine
The same words also carry your brand voice and tell search engines what the page is about. These goals are not in conflict. A description that uses the plain terms shoppers search for, written in a consistent tone, serves all three readers at once: the buyer, the brand and the index.
Action Step
Pick one product you sell. Write down every question a first-time buyer might ask about it before purchasing, aiming for at least ten. Then read your current description and tick each question it answers clearly. The unticked questions are your first rewrite list.
This lesson is educational and reflects general practice. Results depend on your situation, market and effort; adapt what you learn to your own context.