With the Tools menu, you can perform operations related to DB, Sysvol and msdcs records.
DBcheck: Some transactions and changes in the enterprise directory database are not replicated to other domain controllers. DBCHECK checks the objects in the database by examining them for consistency.
DBcheck ReIndex: Sometimes databases take up a lot of space and their consistency can be broken even though there are deleted records. DBCHECK ReIndex audits and re-indexes the enterprise directory database.
Sysvol Check: SYSVOL is used to control sharing and finds ACL (Access Control List) and GPO issues if any.
Sysvol Reset: Used to reset the permissions on the SYSVOL folder to default.
Refresh MSDCS Records: Refreshes the msdcs records on the domain controller.
Deleted Object Cleaning: Permanent cleaning of logically deleted objects is done here.
SYSVOL is a shared folder located on domain controllers. This folder contains the GPO settings. In replication between domain controllers, SYSVOL is also replicated.