Slot 1: product name (as the buyer searches it)
The product name field is not a marketing field. It is a search field. Buyers type the words they would use to find your product, not the words you use to describe it. A 'stainless steel double-wall insulated water bottle' is a great product name; 'HydraMax Pro' is a great brand name. Use the first in the product name field.
If the product has multiple valid search names, pick the one with the most search volume. The keyword extractor can help you confirm which name wins on your target platform.
Slot 2: platform (and why it changes everything)
Always specify the platform. Amazon, Shopify, Etsy, eBay, and direct-to-consumer sites all have different title length conventions, bullet structures, and trust signals. The model adapts the output to the platform if you tell it. Without the platform, the model falls back to the average of all of them, which is never optimal.
If you sell on multiple platforms, generate a separate output for each. The cost is small; the relevance is large.
Slots 3-6: audience, features, differentiator, tone
Audience in one specific sentence. 'Busy parents packing school lunches' beats 'everyone'. Features as facts separated by commas. Differentiator as one phrase. Tone as one word. Each slot is constrained on purpose; the model produces better output when each slot has a clear job.
If a slot does not apply, delete it from the brief rather than leaving it blank. A blank slot becomes a soft hint that the model will fill in, often badly.