It looks like the first character is being trimmed from all source_description values, for example:
https://us.api.blizzard.com/data/wow/toy/1?namespace=static-us&locale=en_US
{
"_links": {
"self": {
"href": "https://us.api.blizzard.com/data/wow/toy/1?namespace=static-10.2.0_51825-us"
}
},
"id": 1,
"item": {
"key": {
"href": "https://us.api.blizzard.com/data/wow/item/1973?namespace=static-10.2.0_51825-us"
},
"name": "Orb of Deception",
"id": 1973
},
"source": {
"type": "DROP",
"name": "Drop"
},
"source_description": "rop: World Drop",
"media": {
"key": {
"href": "https://us.api.blizzard.com/data/wow/media/item/1973?namespace=static-10.2.0_51825-us"
},
"id": 1973
}
}