Not the sharpest tool in the shed

exp.

Heard in Sligo

Not very intelligent. A bit slow or vague.

In use

A: "Do rabbits lay eggs?" "B: 'Yer not the sharpest tool in the shed, are yeh luv?!'"

Posh English

A: Do rabbits lay eggs? B: You are not the sharpest tool in the shed, are you, my dear?!