I took a quick look at the plugin All in One SEO Pack.
It has a built in data migration function which looks for descriptions set to any Post Type (including Simple Links).
It does a blind search for any descriptions and if found it will display a big “Update Database” button.
When pressed, this button does a blind replace of any descriptions in the database using the following query. $wpdb->query( "UPDATE $wpdb->postmeta SET meta_key = '_aioseop_description' WHERE meta_key = 'description'" );
Unfortunately, there is not much I can do about it. My plugin is highly extendable. If I change the link descriptions to something else it could potentially break many peoples custom sites/plugins.
Perhaps you could get the author of All in One SEO to only run the script if someone is updating from and old version of the plugin instead of a blind search and replace.