What attributes must have a loop-ready audio file?

Hi! I perform songs for video production and have doubts about how must I edit my songs so as to be useful for video production, specially when they have to be looped.

A few days ago one of my files was rejected because it has a tempo of 99.9732 bpm instead 100 bpm. How much precise does the tempo must be? Does it really matters?

Do video producers really need the looping properties to be embedded in the file info tags (wave properties)? Like Loop info, Sampler tags...