To add tools to a Work Order, go to the Tools browser, select the tool you want to add, and edit its details.
Then, in the Parts section, add the Main Unit of the Work Order as a PN.
By doing this, that tool will appear in the Work Orders that have that Main Unit.
Then, in the Parts section, add the Main Unit of the Work Order as a PN.
By doing this, that tool will appear in the Work Orders that have that Main Unit.