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