I found this: "As we announced in November 2015, customer experience is a factor we consider in search placement. When determining customer experience on Etsy, we look at positive reviews, completed About sections, and completed Shop Policies (FAQs and seller details are not factored into search ranking). Selecting these new Shop Policies are an easy way to give shoppers the information they’re looking for while slightly improving your placement in Search."
Best I can tell, the only place to add the extra details is in the FAQ section, altho I am not sure how prominent that is when someone is viewing your shop.