First of all create a new tool database in extras. Then make it standard database. The original one may be deleted.
You have 2 possibilities for declaring of a milling cutter. You may declare a milling cutter in every milling strategy and save it; otherwise open your tool table under Extras and input your tools there. All required parameters will be requested during creation. It’s recommended to declare an appropriate materiate material for each milling cutter. It would later make the overview better.