You find the information about WmMonitor in Monitor user guide however you will not find any documentation on WmRoot services as it is internal to sag. If you know anyone in rnd team you have some chances to get them.
the services under those packages under pub.xxx are public exposed services by SAG and only those are available to the third party developers to use. As for those wm.xxxxx services, they are meant for internal SAG modules usage and it could be modified and deprecated on newer release. Therefore it’s not suitable to use those services in your code, and also the reason why SAG doesn’t provide details/bulit-in services documentation to those services.
Please refrain from using those services directly.