How to write product descriptions for AI shopping agents

Most advice about writing for AI agents stops at “add more keywords.” That misses what actually happens to your description. An AI shopping agent does two things with it: it matches it to a shopper’s question, and it condenses it into a summary. Good copy helps with both. This post is mostly about the second, because that’s where descriptions go wrong in ways a merchant can prevent.

What happens to your description

For a Shopify store, the path usually runs through Shopify Catalog:

• Shopify reads it. The catalog’s own description, top_features, tech_specs and unique_selling_points are fields Shopify marks as “generated or enriched by Shopify” (Global Catalog docs).
• The channel reads that. OpenAI says ChatGPT “may generate simplified product titles and descriptions based on information it receives from third-party providers” (Shopping with ChatGPT search).
• Shopify’s ranking tools measure it. The Listing quality meter in Sales channels > Agentic includes description completeness, which “measures the word count of your product description” (Managing agentic storefronts).

So your description gets summarized at least once, maybe twice, before a shopper reads anything. Write it so a summary can’t easily change its meaning.

The rules

1. Say what it is in the first sentence

Start with a plain noun and who it’s for: “A mineral sunscreen lotion for babies and kids, SPF 50.” Not “Meet your new summer essential.” A shopper’s question is plain words, and a summarizer picks up whatever the opening sentence says the product is.

2. Use exact numbers, and use the same ones everywhere

Ages, sizes, counts, concentrations and SPF are where summaries slip, because one character changes the meaning. Write “for ages 4 and up,” not “for kids.” Write “60 capsules,” not “a two-month supply.” Then make sure the same number appears in your title, variants, product details fields and images. If they disagree, a summary has to pick one.

3. Be precise about what it’s free from, and what it isn’t

“Free-from” claims are short, popular and easy to over-apply. If your product contains essential oils, “fragrance-free” is a claim to think twice about, and “no synthetic fragrance” may be the accurate one. If it has preservatives, name them rather than leaving the list to an ingredient panel.

In our read of 192 top-ranked products on Sep 24, 2026, we found two described to AI agents as “fragrance-free” whose own ingredient lists include fragrance or essential oils (how we checked). The examples are in the study.

4. Put safety information in the text, near the top

Warnings, age limits and “consult your doctor” lines are often in a tab, an accordion or an image. Put the important ones in the description itself. Shopify asks merchants selling through ChatGPT, Copilot, Google and Meta to “ensure that your product descriptions include any relevant legal disclosures in the first 6,000 characters” (Selling on ChatGPT).

A shorter version of the same rule: if you’d be upset to see a claim dropped from a summary, don’t leave it only in a place a summarizer may not read.

5. Don’t leave facts only in images

Badges like “vegan,” “BPA-free” or “dermatologist tested” are often only in product photos. A text model can’t count on reading them. If the claim is true and matters, write it out. If you can’t back it up, don’t put it in the image either.

6. Answer the questions shoppers actually ask

Shopify’s guidance for AI is to “include sizing guides, material information, and care instructions as applicable,” along with “detailed product specifications and technical details” (Optimizing your store for AI). Think about the follow-up questions your support inbox gets: does it fit a standard crib, can it go in the dishwasher, is it safe while pregnant. Answer them in the copy. That’s the material agents match against.

7. Detail beats adjectives

Shopify’s listing-quality meter counts words, but the words that help are facts. “Luxuriously soft” gives a summarizer nothing to hold on to. “100% long-staple cotton, 400 thread count, sateen weave” gives it three claims it can repeat accurately.

8. Keep one version of each fact

Many stores have the same fact in five places: description, metafields, a tab, a PDF and an image. Over time they drift. Choose one source for each fact and update the others from it. If your real product data lives in metafields, Shopify’s Catalog Mapping lets you point the catalog’s description or title at them (Mapping your product data sources).

A before and after

Here’s a made-up baby balm, written two ways.

Before: “Our cult-favorite balm is pure, gentle magic for your little one’s skin. Clean ingredients, no nasties, loved by parents everywhere.”

That’s 20 words and almost no facts. “Clean” and “no nasties” invite a summarizer to fill in the category’s usual claims, like fragrance-free, preservative-free and hypoallergenic, whether or not they’re true.

After: “A balm for dry and chapped skin on babies and kids, made with shea butter, calendula oil and beeswax. Scented with a small amount of lavender essential oil. No added preservatives, because the formula contains no water. Patch test before first use. For external use only. 2 oz tin.”

Every sentence is a claim a summary can repeat accurately, and the one that would most often go wrong, the scent, is stated outright.

Check the summary, not just the copy

Good copy lowers the odds of a bad summary. It doesn’t remove them, and you can’t see the catalog’s version of your product from the product editor. We explain what’s in that version in What Shopify’s AI adds to your listings, and what to do when it’s wrong in AI getting your product wrong?

Hearsay does the checking. It reads what Shopify’s catalog tells AI agents about each product, compares every claim with what you wrote, and tells you which ones contradict you and which you never said. The free scan covers 5 products, and the paid plans cover up to 2,500 products with daily rechecks.