Judge gives direction to fools (6)
I believe the answer is:
assess
'judge' is the definition.
(assessing is a kind of judging)
'direction to fools' is the wordplay.
'direction' becomes 's' (S is an example).
'to' says to put letters next to each other (I've seen this in other clues).
'fools' becomes 'asses' (ass is a kind of fool).
's' put after 'asses' is 'ASSESS'.
'gives' is the link.
(Other definitions for assess that I've seen before include "Rate, evaluate" , "Evaluate worth" , "Judge the quality of" , "Gauge, evaluate" , "Judge the worth of something" .)