Disclosed is a release tool used to separate portions of a tool string. One release tool includes a main body, a bolt housing coupled to the main body and defining a bore for receipt of a separation bolt therein, the separation bolt being configured to couple the bolt housing to a lower sub, and a trigger mechanism communicably coupled to the separation bolt and configured to send an electrical signal to the separation bolt whereupon the separation bolt breaks and thereby allows the lower sub to separate from the bolt housing.