> have a tool call that gives the customer a discount, without it getting used when it shouldn’t?

without comment on the rest of your post, a lot of discounts are just dark patterns, buy 2 for $10 or one for $6 is one of the oldest dark patterns around, and a lot of people fall for it, when they really didn't need that much whatever it was they were buying. In fact there are laws outlawing these practices coming into force for various types of products (alcohol, sugar) .

Other types of discounts like loyalty are more vague personally I think are a minor dark pattern. Negotiated discount on bulk purchases b2b are a different class, but it could be argued that you should only get the discount that the seller saves on logistics.

I'm just pointing this out because its very normalized, 'signup and get 3 months free', 'buy 2 get one free' etc, people dont bat an eyelid at, the same as advertising , but they are all just the earliest versions of dopamine hacking and dark patterns that consensus now is coming around to say probably isn't the best thing when scaled beyond a simple one to one interaction. Why are snapchat dopamine hacking with streaks but your local coffee shop stamping your card for your 10th coffee free different?