Go to UO-Cah.com put base pet stats into the pet intensity calculator and that will tell you how good it is, if it's untrained.
If it's trained put the finished pet stats into the trained pet intensity calculator. That will also tell you how good it is.
However, if it's trained the calculator will not tell you if it's a good pet as to how it was built. It will just tell you what the intensity value of all of it's stats are. Generally a good build for a good Bane is Chiv/AI. There are a lot of other build options. I have a Magery/AI/Exp Goo Bane and it's great.