In a medium saucepan over high heat, add the water, agave syrup and sugar bring to a boil. Turn off heat and add the tea bags. Let steep 5 minutes. Remove the tea bags and add the 2 cups of ice cubes. When tea is cool, add the vodka.
To serve, put a few ice cubes in each glass with about 2 or 3 fresh mint leaves and muddle. Add the tea until 3/4 full, and top with ginger ale. Sir and garnish each glass with a sprig of fresh mint.