Fool set out to get things of value (6)
I believe the answer is:
assets
'things of value' is the definition.
(I've seen this in another clue)
'fool set out to get' is the wordplay.
'fool' becomes 'ass' (both can mean a stupid person).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'to get' indicates putting letters inside.
'set' with letters rearranged gives 'ets'.
'ass' placed within 'ets' is 'ASSETS'.
(Other definitions for assets that I've seen before include "(Person's) property" , "worldly goods" , "One's valuable possessions" , "Valuable property" , "Property owned by person or business" .)