This is small enough to hold in the palm, its chrome plated, and the name is on the back side, so of course I won't show you that, would give away the ball game. Been 25 years since it was in common use in shops.
A carb tool I'm pretty sure. Used to set the accelerator pump?
It is a carb tool, for the accel pump or maybe setting float level, says CARbureTER on the flip side.