I've had this edge a long time now, and despite fighting with my familiar constantly I've not evaded anything once. Not even normal random evades. My dex is only 21, but I would have thought for the cost I'd have seen something. So I wanted to make sure it's actually working as intended, thanks!

How many times do you see the word 'evade' in the Familiar Agility helpfile?

There's a reason for that.