To add a new tool, position the mouse over the tool in the Tool Classes list that you want. Press the left mouse button and drag the tool onto the position in the Active Toolset that you want the tool to occupy and let go of the mouse button. To be a little more precise drag so that the tip of the arrowhead is in the center of the tool or space that you want the new tool to be above.
The tool will appear in the position you have placed it. It will have a default configuration. Control-click or click with the right mouse button to modify the tool options. When you do change the options for a tool, the icon for the tool might be modified. For example the Tree Diagram tool has three icons: 
, 
and 
. The first shows that the causes of a variable will be displayed, the second that the uses of a variable will be displayed, and the third that both causes and uses will be displayed. You can also modify tool options directly from the Workbench.
