Programmatically read both per-tab Terminal.app titles
Try:

tell application "Terminal"
    set myTabs to every tab of window 1
    set myData to {}
    repeat with aTab in myTabs
        set aTab's selected to true
        delay 0.2
        set windowTitle to name of window 1
        set customTitle to aTab's custom title
        set end of myData to "Window:" &amp; windowTitle &amp; return &amp; "Custom Title:" &amp; customTitle &amp; return &amp; return
    end repeat
    display dialog (myData as text)
end tell