You can indeed.
In order to change your description for your Rust server, you will need to change the serverauto.cfg file in your "server/experimental/cfg" folder inside your servers FTP directory. (Directions at the bottom of this ticket.)
1. Access your server directory with an FTP editing client (see instructions at the end of the ticket on how to do this)
2. Navigate to the "/server/experimental/cfg" folder
3. Locate the file "serverauto.cfg" If the serverauto.cfg is not there you will need to make a new file and name it serverauto.cfg
4. Edit "serverauto"cfg" with Notepad++
5. Add a new line at the bottom of the "serverauto.cfg" file and put this: server.description "whatever you want the description to be"
6. Replace whatever you want the description to be with your description
Additionally, if you want a header image, you can add the line server.headerimage "url.jpg"
To edit/upload/save/delete files via FTP, use the following method:
1. Stop your server from the panel
2. Log in to FTP using WinSCP (a free FTP software) using the connection details found in the "FTP Details" section of the game server control panel
3. Navigate to the directory you wish to upload or edit a file
4.After uploading your files in the proper directories, start your server from the panel
You may found a download link for WinSCP here: http://winscp.net/eng/download.php