Maybe they are being vague on purpose, and specifically went out of their way to not offer more specific or detailed guidelines. If they are trying to model themselves after the Hugo awards, it fits right in where the Hugo awards tries to be very vague about what counts as science fiction so that it is left up to the community via voting if it is appropriate or not. It has resulted in an occasional win that some fans think belong more in other genres than science fiction, but that is considered the price of letting the community be able to define it instead of some small committee.
Maybe they are being vague on purpose, and specifically went out of their way to not offer more specific or detailed guidelines. If they are trying to model themselves after the Hugo awards, it fits right in where the Hugo awards tries to be very vague about what counts as science fiction so that it is left up to the community via voting if it is appropriate or not. It has resulted in an occasional win that some fans think belong more in other genres than science fiction, but that is considered the price of letting the community be able to define it instead of some small committee.