I don't actually know if a tool/site like this would be a good or bad thing.
Some people are mighty protective of their characters, and others are evil enough to purposely steal unique designs and pretend they didn't.
By having them all listed out in the open next to each other, it could be troublesome in some cases. Imagine the trouble you'd have to go through if someone registered their stolen design before the original creator. Or, in rare cases, characters that are too similar could cause a ruckus to more sensitive people that think their character is actually super original. And what would prevent trolls from creating obnoxious fakesonas just for attention, or registering someone else's fursona without their permission? It would have to be moderated pretty heavily.
Honestly, I think for the most part it's kind of unnecessary.
What would the tool even be used for, besides just the random encounter where you recognize a design around the 'net and want to find out the characters name/owner?
The only other thing I can think of is for people to gather ideas on what to do with their own fursona, and that's easily done by searching around the web anyway.