He's not the sharpest tool in the shed or the box.

他不太行。

So, " he's not the sharpest tool in the shed" means he is stupid, not clever.

所以，“他不是棚里最锋利的工具” 的意思是他很愚蠢，不聪明。

Now, maybe creative but the teacher said, " Duh, he's not the sharpest tool in the shed."

也许是有创意，但老师说：“兄弟，他不是棚里最锋利的工具。”

And in the same way, we could use he's not the sharpest tool in the shed or the box.

同样的，我们可以用 he's not the sharpest tool in the shed or the box。

He means well. He's just not the sharpest tool in the shed.

他没恶意 他只是和人打交道脑子不好用。