Shade
Monster Junkie
I don't think it's necessary. As the edition progressed, it's one of those abilities that moved into the "unspoken universal rules". 
Sneak attack generally doesn't need to be described either, but I wanted to give it the ability to scale as they improved.
Rapier and light crossbow appeal.
Updated.
Skills: 18 ranks
Hide and Move Silently, of course. Maybe Bluff and Sleight of Hand? We might consider some racial bonuses as well.
Feats: Improved Initiative (B), Weapon Finesse, 1 more

Sneak attack generally doesn't need to be described either, but I wanted to give it the ability to scale as they improved.
Rapier and light crossbow appeal.
Updated.
Skills: 18 ranks
Hide and Move Silently, of course. Maybe Bluff and Sleight of Hand? We might consider some racial bonuses as well.
Feats: Improved Initiative (B), Weapon Finesse, 1 more