Tooltip hack Rated 5 out of 5 stars

If you want I tooltip for extension in statusbar find on your system file:
C:\Users\ACCOUNT_NAME\AppData\Roaming\Mozilla\Firefox\Profiles\FF_PROFILE.default\extensions\cachetoggle@pau.santesmasses.net\chrome\content\cachetoggle.xul

and change line from
<statusbarpanel context="CacheToggle-StatusContextMenu">
to
<statusbarpanel context="CacheToggle-StatusContextMenu" tooltiptext="Red: Cache OFF">

This is dirty hack!