Tessa returned something valuable (5)
I believe the answer is:
asset
'something valuable' is the definition.
(I've seen this in another clue)
'tessa returned' is the wordplay.
'returned' says the letters should be written in reverse.
'tessa' in reverse letter order is 'ASSET'.
(Other definitions for asset that I've seen before include "Plus point" , "Anything of value" , "Item well worth having" , "Item conferring advantage" , "A thing of value" .)