You can provide your toads with a broken flower pot or several stones under which they can burrow. Although they live on dry land, they have to have water in which to breed. In the pond these guys will eat mosquito larva and other bugs that frequent the area. The tadpoles will nibble on the algae that coats the sides of your pond. They can't get rid of massive amounts, but the amount they devour helps maintain the balance of a healthy pond.
Toads eat far more bugs and slugs than they eat small fish.
If you've had a water garden for any length of time, you know that it is all too soon that the pond is over full of fish. The toads help with population control. Breeding Courting frogs expand their throat skin and cause it to vibrate as it deflates. That's what makes their croaking noises. Individual frogs have different calls that can be recognized by other frogs.