How to run your own AI agent pick test for your product category, step by step
You cannot see inside a shopping agent's decision, but you can recreate the core of it. This playbook adapts Slobodan Manic's published method into a test a small brand team can run in an afternoon and repeat every month.
Brands have always been able to check where they rank on Google. Shopping agents took that away. Each agent asks a model to choose from a list, behind instructions nobody outside the company can read. As Slobodan Manic put it after testing three Claude models on Shopify's catalog: "With agents, everyone gets their own version of the decision, inside an app the store never sees, and there is nothing to monitor."
But part of the decision can be recreated. Manic's published test is a template, and its last recommendation to stores is simply: test your category. (We charted his results in today's data piece.) This playbook turns his method into steps a small brand team can run.
What you need
- A list of 3 to 6 shopper requests that matter for your category. Use the words customers use: "protein bar," "mineral sunscreen SPF 50," "kids' water bottle."
- A way to get the catalog results an agent would see. For Shopify's catalog, the Shop MCP changelog gives a command-line shortcut: install with
npm install -g @shopify/shop, then runshop search "your request". Search needs no API key. - Access to at least two AI models. Chat apps work for a small test; an API or a coding tool makes repeated runs much easier.
- A spreadsheet.
If you don't sell on Shopify, the method still works. Build the list from whatever an agent in your channel would see: a retailer's search results, a Google Shopping page, a marketplace listing grid.
Step 1: Freeze the list
Run each request once and save the top 20 results with the fields an agent receives: title, store, price, rating, review count, a one-line summary and the first few features. Note the date and whether you were signed in. Manic searched as an anonymous US buyer.
Freezing matters. If the list changes between runs, you can't tell whether a different pick came from the model or the catalog. Every run in your test should use exactly the same saved list.
While you are here, do the first and cheapest check: read your own products' records. Is the review count what your product page shows? Is the summary accurate? In Manic's test, one bottle's catalog record showed about 68 times as many reviews as the brand's own page, and two of the three models picked it heavily on that figure.
Step 2: Write one short instruction and keep it fixed
Use something close to Manic's: you are a shopping agent; a person asked you to buy something; here are the products the catalog returned; choose one and reply with the product number and a one-sentence reason. Ask for a fixed format so tallying is easy.
Then add the shopper request, which in the first run is only the search words.
Step 3: Run each model many times, fresh each time
Each pick should be a new conversation with no memory of earlier picks. One answer tells you almost nothing; you are looking for the model's habit.
| Run | What changes | Suggested picks per model | Manic's run size |
|---|---|---|---|
| A. Baseline | Search words only | 20 to 50 per request | 50 per search |
| B. Shopper need | Add a real need, such as a budget, skin type or diet | 20 to 50 | 100 per version |
| C. Position | Same list, reversed order | 10 per version | 10 per version per search |
Source for Manic's run sizes: Slobodan Manic via Search Engine Journal. Suggested ranges are our recommendation for a smaller test.
If you are running by hand in a chat app, start smaller: 10 picks per model per request will still show whether a model has a strong favorite. Manic found each model's favorite product took between 67% and 94% of its picks on average, so a clear habit tends to show quickly.
Step 4: Add a real shopper need
Repeat run A with one thing added that real customers say: "under $25," "for oily skin," "gluten-free," "for a toddler." Pick needs your product genuinely serves.
This is the run most likely to tell you something you can act on. In Manic's sunscreen test, adding "under $25, for oily skin" took every model off the catalog's top product, and a listing that said "without clogging pores" won a third of one model's picks despite the lowest rating in its group. If your product serves the need but doesn't win, the reasons will usually show why: a competitor's listing says the words, and yours doesn't.
Step 5: Reverse the list
Run the baseline again with the list in reverse order, so the top product goes from first to last. Manic found the effect was strong on some searches and absent on most, and no model ever mentioned position in its reasons. You want to know which kind your category is. If position matters a lot, your catalog rank matters more, and the review and relevance signals that drive it deserve more attention.
Step 6: Tally picks and code the reasons
For each run, count picks per product per model. Then read every reason and tag what it cites.
| Product | Model | Picks | Cites review count | Cites rating | Cites price | Cites a need phrase | Cites a claim | Exact phrase quoted |
|---|---|---|---|---|---|---|---|---|
| Your product | Model 1 | |||||||
| Competitor A | Model 1 | |||||||
| Your product | Model 2 |
The reasons are the most valuable output. They tell you which facts the model uses, which phrases it repeats, and whether it is repeating them correctly. In Manic's data, phrases like "clinically proven" and "11x faster" came straight from listings into the models' reasons. If a model is repeating something from your listing, make sure it is something you can stand behind; we argue why in today's think piece.
Step 7: Change one thing, then retest next month
Pick the single highest-value fix the test suggests:
- A wrong or odd catalog fact. Fix the source: your product data, your review app's sync, or your feed.
- A need your product serves but your listing doesn't state. Put it in the title, summary or first features, which is all the models in the test saw.
- A claim you would not want repeated. Soften it, substantiate it or remove it.
Shopify's own advice in its Muse post is the same in spirit: "Agents can only recommend what they understand," so clear titles, structured attributes, complete variants and reviews matter. Make the change, wait for the catalog to update, and rerun the same frozen-list method with a fresh list. Keep the requests and instruction identical so month-to-month results are comparable.
What this test can and can't tell you
It can show how models behave on your category's real catalog data, which of your facts and phrases they use, and whether a listing change moves picks. That is useful, cheap and repeatable.
It can't tell you what a specific app will do. ChatGPT, Gemini, Claude Duet and Meta's Muse each add their own instructions and, increasingly, the shopper's history. As we wrote in stop asking where you rank, there is no single position to own. Treat the test as a view of the layer underneath every app, not a ranking.
If you want this done continuously across many requests and assistants, XENA Intelligence builds that kind of tracking for consumer brands, with SearchPanel covering individual products. But the spreadsheet version above will answer the first question most brands have: when an agent chooses in our category, what does it read, and does it choose us?
A one-afternoon version
If you only have a few hours:
- Choose your single most important request.
- Save the top 20 catalog results.
- Ask two different models to pick, 10 times each, fresh each time.
- Add one real shopper need and repeat.
- Read all 40 reasons and highlight every phrase that came from a listing.
That is enough to find your first fix.
Questions
Can a brand see what an AI shopping agent sees?
Partly. Shopify's Shop MCP and its shop command-line tool return the same catalog results an agent receives for a search, including store, price and stock. What you cannot see is each agent company's private instructions.
How many times should you run each test?
Enough to see a pattern rather than a coin flip. Slobodan Manic used 50 picks per model per search for his main runs and 10 per version for position tests. Fewer runs can still show a clear favorite, but treat small differences cautiously.
Which AI models should a brand test?
At least two model families, ideally the ones behind the assistants your shoppers use. Manic's test showed three models from the same company disagreeing completely, so results from one model do not generalize.
What should you change after the test?
Fix wrong catalog facts first, then make sure your listing's first lines state the needs your shoppers name in plain words, and remove claims you would not want an agent to repeat.
Sources
- Add shopping and Shop Pay checkout to any agent with Shop MCP. Shopify Developer Changelog, Oct 13, 2026.
- 3 AI Models Shopped Shopify's Catalog: Each Picked A Different Winner. Search Engine Journal (Slobodan Manic, originally on No Hacks), Nov 2, 2026.
- Ready for Muse, and whatever's next. Shopify, Nov 3, 2026.
How we work: every figure in this piece comes from the sources above, which we opened and read before publishing. Anything labeled illustrative is an example, not data.
Related tips
- Should you let AI shopping agents buy from your store?
- How do you check whether ChatGPT recommends you?
- What do you do when an assistant gets your product wrong?
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