If you want to know if your technicians are working a full day then it's important to track all of their activities. "Screwdriver" time is when they are at a client site and eAutomate by default will track Travel+Screwdriver time. However if they are returning to the shop for parts or a meeting this is not typically tracked.
There are 2 options to track this non screwdriver time, Dummy Calls and TimeCard Entries.
Up to about 2014 Remote Tech limitations meant Dummy Calls were needed but best practice now is to use Time Card entries only and no dummy calls.
See here for using TimeCard Entries.
Note (4/24/13) Remote Tech 13.1 due out 4/26/13 has the option for you to require the tech to account for unaccounted time. If they close a call at 3PM and dispatch to a call at 10AM the next day RT will ask them to account for whatever they did for the missing hours.
It is also important that you invoice shop work to the contract or equipment when applicable to ensure costs are accurately recorded.