Hi there Jasmine,
Actually, early December is a great time to visit The Walt Disney World Resort. You'll kind of get to experience the best of everything... cool temperatures, Holiday Decorations and events, and lower than usual crowds.
Since you're traveling just before the Holiday school breaks begin, you'll most likely notice that the crowds aren't as heavy as normal. Early December, according to history, is usually one of the least crowded times to visit since schools are still in session, and many families are holding out until the breaks begin later in the month.
Honestly, if your plane arrives at noon, by the time you check into your hotel and head to the parks, it will probably be 1:00 or later. I would suggest spending your half day in either Epcot or Disney's Hollywood Studios. I feel like Magic Kingdom always deserves a full day, with an early start, and Animal Kingdom closes at 6, so you wouldn't have much time there.
Epcot will be open until 9:30 that evening, and don't forget to check out
Holidays Around the World while you're cruising World Showcase!
Best Wishes,
Amanda F.