Product descriptions that answer the questions your DMs keep asking
Where a product description lives for an Instagram shop, which line answers which repeated DM question, and what Baymard and Nielsen Norman Group found.
Published: November 3, 20263 min read

Everyone reads a product description and few shops write it well. Baymard Institute found in usability testing that every user turned to the description at some point to judge whether an item suited them, yet only 22% of the sites it reviewed structure descriptions around highlights. Those figures come from web shops, not Instagram captions. This article is one piece of the guide to increasing online shop sales.
A product description lives in three places
The caption, the catalogue and the storefront product page each have a different job.
- Caption: the most important line goes first, because Nielsen Norman Group found readers read more at the start of a text.
- Catalogue: complete, exact details for every product; the DM assistant answers from here.
- Storefront page: the same catalogue, shown to someone arriving from a link.
Public posts from business accounts can now be indexed by Google too, with conditions covered in Instagram SEO. Still, full product detail belongs in the catalogue, not in a caption that sinks under newer posts.
Every repeated DM question is a missing line
"What is it made of?", "Will size 38 fit me?" and "Is the colour really like this?" each have a one-line answer. The lines below are examples, not standards.
| Field | Example line | Question it removes |
|---|---|---|
| Fabric | Linen with a viscose lining; creases a little. | What is it made of? |
| Measurements in cm | Size 38: chest 92, length 95. | Will size 38 fit me? |
| Model height and size | Model is 170 cm and wears size 38. | How does it sit on the body? |
| True colour | Photos unfiltered, in daylight; the cream leans slightly ivory. | Is the colour really like this? |
| Season and use | For spring and autumn; needs a layer under it in deep winter. | Can I wear it in winter? |
Two to six features, each with a short headline
Baymard recommends two to six core features per product, each with a short headline and one paragraph, and the rest in a plain list. Nielsen Norman Group, after studying 49 shops, gave no percentages but four rules: be complete without being wordy, put the key point first, explain unfamiliar terms, and keep details consistent across variants. Both studied web shops, not Instagram captions, so treat these as direction, not law.
What does not work: copied text, one text for every colour, empty adjectives
- Copying the supplier's text: every other seller has the same sentences, and they say nothing about the colour and size you actually ship.
- One text for every colour: the structure should match across variants, but colour and size details must differ; a cream description beside a black photo creates returns.
- Words like "amazing" answer no question.
Writing a product description in six steps
- 1Hold the item and measure it yourself; check the supplier's numbers.
- 2List the questions DMs repeat for this product.
- 3Pick two to six core features, each with a short headline and one sentence.
- 4Put fabric, measurements, model size and true colour in the first lines.
- 5Write each colour and size's own details with the same structure.
- 6Shorten the caption from this text last.
Where to start tomorrow morning
Open the last thirty customer DMs and note every question that appears more than once. Write the top three into the catalogue entry of your best seller, then show only those lines to a friend and ask for its size and fabric. Pair it with product photography with a phone, and see automatic DM replies for the rules around automated answers.
Frequently asked questions
How long should a product description be?
No source gives a number. Nielsen Norman Group says only to be complete without being wordy, so the questions it must answer set the length. If the first line carries the key point, the rest can stay in the catalogue.
Can I write a product description with AI?
A draft is fine, but a tool has not seen your item. Fill in numbers, fabric and measurements from the item itself, and delete any sentence that offers nothing checkable, such as "amazing quality".
Where should the size chart go?
Put each size's measurements in the product text and keep the full chart in a highlight. Keep the order and unit the same for every size so buyers can compare sizes at a glance.
When should I rewrite a product description?
When the same question shows up in DMs again, or a return happened because of something the text missed or got wrong, such as colour or size. A monthly look at DMs and returns will show both signals.
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