Also, drop the chain, and see if there is any roughness as you turn the cranks. There is a lot of leverage, so it is difficult to feel (easier if you remove the cranks).

But, with the cranks on, also wobble the crank back and forth (perhaps towards the chainstays. Any wobble is bad.

If your bottom bracket is cup & cone, then there is some maintenance and adjustment possible including replacing bearings if needed. Other than roughness noted above, it is hard to tell if the bottom bracket has pitted without taking it apart.

If your bottom bracket is Shimano sealed, then they're not serviceable.

Some brands of sealed bottom brackets like IRD bottom brackets are theoretically serviceable, although I don't know if many people do it.