I’ve noticed that the open command in SD does not return a result.
In most apps the of the open command is a reference to the document/window/tab that opened. For SD 6 and 7 it’s “missing value”.
on open (itemList)
local thisScript
repeat with thisItem in itemList
tell application "Script Debugger"
set thisScript to open thisItem
end tell
end repeat
end open
–> Script Debugger 7.0 (7A33)
–> Script Debugger 6.0.8 (6A221)
–> Mac OS 10.11.6 (15G19009)