It's kind of hard to explain. It’s a neutral word really. But if it had to be positive or negative, it'd be a negative word. You normally use this word when referring to someone:

Who ignores counsel
Who is just plain stupid/stubborn
Who makes unnecessary comments
Who makes mistakes
Does dumb stuff
Does something unbelievably stupid/crazy
Who talks shit
Who can't back it up
Who tries to do something and completely fails

You get it? It's really hard to explain. I just want people to know this word SO exists in the slang/lingo world.

Just know it's not a compliment :P

A casual invitation / threat used by an individual that is not afraid of fucking someone up.