There are a few different scripts to perform a drvier/bios update from Dell. 

The recommended agent procedure is: Dell Command Update Scan, Notify and Install

It will check if Dell Command is installed, if not it will install it, then the script will check if there are any updates available, including bios and drivers. 

If updates are found, it will send a notification to the user saying we will be installing the updates that same night, to save their work and leave the computer turned on. 

Here is the notification sent: This computer will be restarted tonight around 10pm to complete important systems updates. Please make sure all your documents are saved before end of day and leave the computer turned on. This notification will be sent again 4h after the first one. Then 6 hours later, the upgrade script will execute and reboot the machine if needed during the install process. 

It can be modified by editing the agent procedure "Dell Command Notification"