Another criteria.. when it gets gets 'fullfilled' there has to be outside verification for it actually happening, rather than some people writing to make it look like a prophecy was fullfilled.
Amoung the ancient Hebrews, the concept of a prophecy was not a prediction of the future, but rather a message from God via someone 'Called by god', to try to steer the nation of Isreal back to God from straying from God. It might come with a warning that 'If you continue on your path, bad things will happen to you', but it is not the fortune telling it has metaphorphed itself into in modern times.