You can use the Networks page to edit the description of a Network resource for the target platform.
In the Web Interface toolbar, select the Platforms tab.
Select the platform, then click Edit.
Under Associations, select the Networks tab, then select Virtual Networks.
In the Networks list, select the network, then click Edit (or double-click the network) to open the Edit Network dialog.
Modify the Description for the Network resource.
Click Save to update the Network resource.
Click Close to exit the dialog.