If this is your first trip and you only have five days, my impression is that you probably won't have the patience to find the "magic" at Epcot. Yes, there is a lot to do. But it terms of excitement it often pales in comparison to the other parks.
Unless you wan't to plan out every single minute of your trip, here is what I would suggest. Plan an afteroon / evening at Epcot during one of your first couple of days. Visit another park in the morning, break for lunch or just a rest back at the hotel, and then go over to Epcot. That will give you pleanty of time for the key attractions (Test Track, M:S, Honey I Shrunk The Kids, etc.), and make sure you stay for Illuminations.
But try to get there on your first or second day. The longer you wait to experience Epcot, the more it is likely to pale in comparison to the other parks.
A half-day will give you pleanty of time to get a taste for Epcot. If you find yourselves wanting more, you will still have 3-4 days left in your trip to shift the schedule.