az tag --help Manage resource tags.

[addaxnasom]

Group
    az tag : Manage resource tags.

Commands:
    add-value    : Creates a tag value.
    create       : Creates a tag in the subscription.
    delete       : Deletes a tag from the subscription.
    list         : Gets the names and values of all resource tags that are defined in a
                   subscription.
    remove-value : Deletes a tag value.