Fill a back-to-school supply cart from the teacher's list with Gemini and Instacart

Posted

Aug 8, 2026 by Amanda Caswell (Tom's Guide)

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Last checked

Oct 17, 2026

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Method:

How we verify

Evidence: Article or interviewA newsletter, journalist or interview account of what happened.

Context: In a comparison test: from a head-to-head chatbot review, not a standalone agent test.

Beginner-friendlyNo logins, payments or coding needed. Low risk: paste the prompt and you should get something useful.

Outcome

Tom's Guide's Amanda Caswell gave ChatGPT, Gemini and Alexa+ the same school supply list: follow it, stick to required quantities, pick reasonably priced items and skip optional ones. Gemini built an Instacart cart, skipped optional items, asked her to approve colours and totalled about $60-$90 ($105 with the optional water bottle). ChatGPT, on her Walmart account, followed the list carefully but slowly for $92.55; Alexa+ added the optional items and reached $251.48.

Agent

Gemini, ChatGPT

The source didn't share its exact prompt, so we wrote this from what it describes.

Run this task now, exactly as written below. Everything you need is here, so start straight away and only stop if something required is missing or a rule below tells you to.

Goal: Turn my child's school supply list into a shopping cart at a reasonable price and stop before checkout.

Fill in before running:
- The supply list (photo or PDF): [ATTACH]
- Grade and child's name for the order: [DETAILS]
- Store or app to use: [Instacart / Walmart / Target]
- Colour preferences, or 'pick neutral': [PREFERENCE]
- Budget: [AMOUNT]

Rules:
- Match required brands and exact quantities from the list.
- Skip anything marked optional, but show what the total would be with them.
- Choose reasonably priced items; don't upgrade to premium versions.
- Stop before checkout; I'll review and pay.
- If a site asks for a login, a CAPTCHA or payment details, stop and hand control back to me.
- Ask for my OK before you pay, book, send, submit or cancel anything.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.

Output: A cart summary: each list item, what you picked, quantity, price, and the total with and without optional items.

You'll know it worked when: every required item is in the cart in the right quantity, nothing optional slipped in, and the total is within budget.

Run this task now, exactly as written below. Everything you need is here, so start straight away and only stop if something required is missing or a rule below tells you to.

Goal: Turn my child's school supply list into a shopping cart at a reasonable price and stop before checkout.

Fill in before running:
- The supply list (photo or PDF): [ATTACH]
- Grade and child's name for the order: [DETAILS]
- Store or app to use: [Instacart / Walmart / Target]
- Colour preferences, or 'pick neutral': [PREFERENCE]
- Budget: [AMOUNT]

Rules:
- Match required brands and exact quantities from the list.
- Skip anything marked optional, but show what the total would be with them.
- Choose reasonably priced items; don't upgrade to premium versions.
- Stop before checkout; I'll review and pay.
- If a site asks for a login, a CAPTCHA or payment details, stop and hand control back to me.
- Ask for my OK before you pay, book, send, submit or cancel anything.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.
- Before handing back, compare the cart line by line against the list and flag any mismatch.

Output: A cart summary: each list item, what you picked, quantity, price, and the total with and without optional items.

You'll know it worked when: every required item is in the cart in the right quantity, nothing optional slipped in, and the total is within budget.

Before you finish: re-read my goal and constraints, check your answer against each one, and list anything you assumed or couldn't confirm.

Source

https://www.tomsguide.com/ai/i-let-chatgpt-gemini-and-alexa-shop-my-kids-back-to-school-supplies-only-one-got-it-right