Slow down shift clicking??

This is pretty simple but dont know how to fix.  I have a tool. I want it to have a magnet ablitites.  So i made a clone of the tool. One has magnet other does not.
If you shift right click it removes the tool and places the other version in the same hand.  All is good

Except when you shift click it goes so fast that it remove tool A, replaces it with tool B, then switches back it tool A. as fast as you can click it does 2 actions. Hope this make sense.
if you shift click with both items it switches back to the other. but its happening so fast you cant get to the other tool unless you just happen to catch the game in between ticks. which is rare. 
 

Any ides would be great