Hi Kelli! Thanks for the great questions! You will receive a receipt that shows the total cost of your meals for your party. They will also list suggested tip amounts to save you from doing math!
Tipping for mousekeeping in your resort is entirely up to you. It is not expected, but it is appreciated. If you do decide to tip, be sure to clearly identify that the money is for the cleaning staff. You might want to bring some envelopes with you labelled mousekeeping so they know it's for them.
The Tomorrowland Dessert Party is buffet style where guests serve themselves, and gratuities are nit expected. Nor are they expected at most quick service spots. Although it is a quick service, Wolfgang Puck Express food is made to order, and wait staff bring your meals. They also clear your table and replenish soft drinks, so if you go, you might want to consider leaving a gratuity. Again, it is totally up to you.
Hope this helps Kelli! Wishing you a magical vacation!