I did an install of a secondary site and accidently put in the wrong description…
Anyway, easy to fix with some SQL commands.
If you use this you can see the current sitenames and descriptions (change CM_XYZ to your database name):
SELECT SiteCode, SiteName, SiteServerName FROM CM_XYZ..SC_SiteDefinition
And here is the way to update it (Change to you database name and the site code of the site you want to change)
UPDATE SC_SiteDefinition SET SiteName = 'My Site Description' WHERE CM_XYZ.SiteCode = 'ABC'
FYI: When running this you will se “Updated X rows… Updated Y rows…” and so on.