If no specific tracks are selected the script will try to work with all tracks in the current playlist or sometimes the entire library.
Some scripts offer a choice of track by track confirmation of changes or fully automatic processing of the selection.
At work, I play my i Pod through my computer's speakers.
The Play Count and Last Played fields get updated when the track ends. You probably have already checked this, but you might check again, to make sure that i Tunes is set to automatically update the i Pod every time you connect.
Test the behaviour of your chosen script on a small group of files first to make sure it does what you want before applying it to large numbers of files.
Please note that some older scripts may crash if they attempt to process "tracks" that are available in i Cloud but not on your computer.
I then unmount the i Pod (click on the Eject i Pod button in i Tunes), and the i Pod ejects. -- "No urban night is like the night [in NYC]..is our poetry, for we have pulled down the stars to our will." - Ezra Pound, poet and critic, 9/18/1912, reflecting on New York City time you connect. I have it set to manually manage songs and play lists as I don't have enough room on my computer to store all the music that is on the i Pod.
I put the i Pod back in the dock, either immediately or the next day, and find that neither the Play Count nor Last Played fields have been updated. X 10.2.3, all updates/security etc, i Tunes 4.2 (72), i Pod (40 GB) updated with latest software. My understanding was that unless you set the i Pod to manually manage songs, it automatically would automatically try to copy over all the songs that aren't on the computer.