Twenty e-commerce prompts for people who write their own product copy, built so an assistant has to show its work. Each gives the model a role, steps, a strict JSON output format and a test plan: run it on good and broken inputs and check the verdict flips. Five sections. Listings and SEO takes 6: listing rework grounded in product facts, SEO title builder, tag miner limited to your catalog, description scoper, compliance pre-check, duplicate-listing detector. Reviews and support takes 4: review triage with escalation rules, negative review recovery, FAQ builder citing the policy line, refund reply. Cart, email and upsell takes 4: a 3-email cart recovery with no fake urgency, bundle builder with margin math after fees, cross-sell pairing scored from catalog data, winback. Pricing and offers takes 4: pricing page copy audit, price-change announcement with number matching, offer guardrail with worst-case stack math, competitor positioning from sourced prices. Catalog QA takes 2: product card QA, honest-claims audit against your files. 10 of the 20 ran during packaging and those results ship in the pack. 9 ran against real artifacts: a live page of 90 product cards and a 26-dataset catalog. The pre-check caught 2 price-in-body flags on our own cards. Every prompt refuses to invent. Missing facts go to gaps, verdicts flip instead of padding, most test plans include a negative test. Paste into any capable assistant, fill the brackets, require the JSON. A spreadsheet copy of all 20 is in the zip. License covers personal and commercial use, no resale of the pack itself.