Tool

Watkins says only "from Old English 'to:l', possibly from old Norse".
Could this be a survivor of a word behind the PIE suffix for nouns of
instruments *-tlo-? I know it's unlikely, particularly since *-tlo-
is only one variant of a presumably equivalent group with *-tro-,
*-dhro- and *dhlo- (from Mallory and Adams), but can someone formally
demonstrate that I've been mislead by a false similarity?
Dan Milton