I find that small "critter keeper" or similar plastic tanks, with a small water dish and paper towel substrate (a thin layer of paper towels that has been rinsed and soaked in treated "frog" water), make good quarantine cages. The small size of the cage and the paper towel substrate make it easy for the toad to catch food, and make cleaning a snap. Get two of them and it makes it easy to move the toad when cleaning. If you end up treating for chytrid or parasites, having multiple identical small tanks makes life so much easier.

PS. Keep the tank in a quiet location with appropriate temp so to not stress the toad...