DOMS: The Good and Bad

Hey everybody.

I have always considered DOMS to be a sign that I did a good workout. But I read on an article that this doesnt nessesarily mean that.

So my questions are.
When is DOMS good, and when does it get to the point that it is bad?
If you dont have DOMS does it mean you didnt stress the muscles enough?

Yesterday I did chest, upper back, and lower back.

Today I can still walk perfectly normally, but particularily my middle back is very tender to the touch.
Did I over do it?

Thanks guys