%image
Probably means it's looking for an item's image.
wrenchImage
hammerImage
Here's some example code with some revised code:
(the old one was styled for an event)
function Player::addItem(%this,%image)
{
   for(%i = 0; %i < %this.getDatablock().maxTools; %i++)
   {
      %tool = %this.tool[%i];
      if(%tool == 0)
      {
         %this.tool[%i] = %image;
         %this.weaponCount++;
         messageClient(%this.client,'MsgItemPickup','',%i,%image);
         break;
      }
   }
}
findclientbyname(heed).player.addItem(wrenchImage);