One way you'll know they're at ease with you will be when you can handle them without them ever doing anything defensive in response, from discharges to inflation and curling to just scrambling to get away. Toads are a little harder to domesticate to that degree than Gray Tree Frogs are but you shouldn't hesitate to try. It's best not to take them up when they're sleeping or hiding but if you see them out and exploring their tank you can take that opportunity to further acquaint them with you. My Tree Frogs let me know they want to have outside time by jumping onto the screen door of their tank and crawling over to the part nearest to me. During the winter they're far less active and eat much less and sleep much more but periodically they will be interested in some socializing. They get agitated climbing on the screen and are all charcoal colored, then get very calm and turn very light gray once they're on my hand. In the winter months they'll just go to sleep on me but in the warm seasons they'll climb all over me.