Advantage to have right element (5)
I believe the answer is:
boron
'element' is the definition.
(I know that boron is a type of element)
'advantage to have right' is the wordplay.
'advantage' becomes 'boon' (both can mean a benefit or asset).
'to have' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'boon' enclosing 'r' is 'BORON'.
(Other definitions for boron that I've seen before include "element needed for steel" , "Metalloid element, B" , "Atomic no 5" , "Chemical element, symbol B" , "component of steel" .)