When you select a schema you've added to the Explorer tree, a summary about the schema appears in the main window beside it, along the top: a breadcrumb and Actions menu, followed by counts of the schemas tables, active tables (ones that you've configured), metrics and monitors. As with datasources, you can also enable and disable all the metadata metrics and data profiles for a schema's tables using commands to the right of the Explorer tree.

In addition, schemas have a Table activity auto metric. Although you can't use the Explorer tree to enable this auto metric, you can add a monitor to it and open any detected incidents.