Listing Description, in the reservation details, is not an important information at all. Having it there does not make sense, but even if it does, its surely less important that the pricing info, which appears always at the bottom, so each time we open reservation details we always need to scroll until we see price details.
i personally never used the description, but i can see it being helpful, maybe to quickly read through, if you have questions from guest, that you think have answers in the descripion.
But we never used it :) we would rather click the property photo, then end up being on the actual listing on airbnb.