Means: "wear a condom".
B kool bag your tool.
by Anonymous November 08, 2003
This is a phrase commonly used by construction workers and contractors as a helpful reminder not to leave hardware on the ground or any other place where it could potentially harm unsuspecting co-workers. The same goes for your penis.
"Hey John. Don't leave your penis on the ground. B kool bag your tool. And don't leave that saw on the ladder either."
by Tyrone Jenkins July 31, 2006