Claims in fields, not prose, means stating each checkable selling point, such as "water resistant to 50 meters", in a named product field as well as in the description. A machine can match a field to a shopper's request with confidence, while the same claim inside a sentence leaves it to guess which words are a specification and which are marketing.
Product copy is written to persuade a person, so the facts arrive wrapped in adjectives. "Built to survive anything the ocean throws at it" persuades. It does not tell a machine whether the watch survives a swim. OpenAI's shopping help page says ChatGPT weighs structured product data such as price and description when it picks products, and a field gives it something exact to weigh.
Which claims belong in a field?
Any claim a buyer could check belongs in a field. Measurements, materials, capacity, compatibility, certifications, care instructions and country of origin all qualify. A claim that cannot be checked, such as "premium" or "built to last", stays in the description for the reader and does not get a field, since there is nothing in it to match.
| Your selling point | As prose (a vibe) | As a field (a fact) |
|---|---|---|
| Waterproof rating | “Built to survive the elements” | water_resistance: 50m |
| Material | “Made from premium organic cotton” | material: organic cotton |
| Dispatch speed | “Ships fast!” | dispatch_time: 24h |
| Compatibility | “Works with most models” | compatible_with: iPhone 14 to 16 |
| Diet / ethics | “Cruelty-free and vegan” | vegan: true |
How do I put claims in fields on Shopify?
Shopify gives every product two kinds of fields for this. Category metafields come from Shopify's product taxonomy and appear once you choose a product category. Custom metafields are the ones you define yourself, for facts the taxonomy does not cover.
- In your Shopify admin, go to Products and open a product.
- Under Category, choose the most specific category Shopify offers, such as Watches rather than Jewelry. Fill in the attribute fields Shopify shows for that category, such as color or band material.
- For a fact the category does not cover, scroll to the Metafields section on the same product and click Add definition. Give it a clear name, such as "Water resistance", and choose a type that fits the value. A measurement takes a number with a unit, and a yes or no claim takes a true or false value. Click Save.
- Enter the value on every product the claim applies to. A field filled on 6 products and empty on 40 leaves 40 products with nothing to match.
- Go to Online Store > Themes and click Customize. Open the product template, add a text block where the specifications belong, and use the connect dynamic source icon to link it to the metafield. The value is now visible on every product page that has one.
- Ask your developer to add the same values to the product's structured data, or follow the snippet below. Our guide to metafields that agents read covers the theme side in more detail.
How do I add a metafield to the product markup?
Schema.org's Product type has an additionalProperty field for facts like these, each one a PropertyValue with a name and a value. If your theme prints Product structured data in sections/main-product.liquid, the lines below can sit inside that Product block. The metafield name in the snippet must match the one you defined, and the line prints only when the product has a value. Paste it before another property in the block, since it ends with a comma.
{%- if product.metafields.custom.water_resistance != blank -%}
"additionalProperty": [{
"@type": "PropertyValue",
"name": "Water resistance",
"value": {{ product.metafields.custom.water_resistance.value | json }}
}],
{%- endif -%}Check the product page in Google's Rich Results Test afterwards and confirm that one Product carries the property. A page must carry one Product, so add the property to the existing block instead of adding a second one.
What can go wrong with a claim in a field?
A field reads as a fact, so an inflated field is easier to catch than an inflated sentence. If the description says 100 meters and the field says 50, the page contradicts itself, and when schema and page disagree explains how a machine treats that. Put the true value in the field, make the description say the same value, and keep the field the same on every page that repeats it, including comparison pages and collections.
How would a watch store do this?
Take a watch store on Shopify with 46 models, where every description mentions water in a different way: "splash proof", "swim ready", "good for the pool". A buyer asks an assistant for "a watch I can swim laps in under 300 dollars". The store adds a Water resistance metafield, fills it from each manufacturer's specification sheet in meters, shows it on the product page next to the price and prints it in the Product markup. Each description now states the same number the field does. The descriptions still sell, and every product now carries the same measured value.
In our study of 216 Shopify storefronts (June 2026), 72 percent failed Entity Integrity, the machine readable product and brand layer where fields like these live. Writing product descriptions for AI covers the description that sits next to the fields.
Common questions
What does claims in fields, not prose mean?
It means stating each checkable selling point, such as a measurement or a material, in a named product field as well as in the description. A machine can match a field to a buyer's request, while a claim inside a sentence is harder for it to tell apart from marketing.
Can an agent read my product description?
It can read the words. It cannot always tell which words are a specification and which are atmosphere, and a field removes that doubt. Keep the description and add the field.
Do I have to remove claims from my copy?
No claim needs to leave the copy. Keep the persuasive sentence for the reader and add the checkable value in a field, and make sure the two say the same thing.
Do Shopify metafields show up in structured data automatically?
A metafield appears only where the theme prints it. Connect it to a block to show it on the page, and add it to the Product structured data in the theme for machines to read it there.
Sources
- OpenAI Help Center, Shopping with ChatGPT Search, read November 9, 2026.
- Shopify Help Center, Creating custom metafield definitions, read November 9, 2026.
- Schema.org, additionalProperty.
- Visibility Mesh, The State of AI Visibility 2026, 216 Shopify storefronts scored June 28, 2026.
The Catalog Assessment reads every product in your Shopify export, up to 1,000. It shows how many carry a description, an SEO title and an image, so you know which products to give fields first.