Marks tool badly in hurry (4,5)
I believe the answer is:
look smart
'hurry' is the definition.
'marks tool badly' is the wordplay.
'badly' indicates anagramming the letters.
'marks'+'tool'='markstool'
'markstool' anagrammed gives 'LOOK SMART'.
'in' is the link.
(Other definitions for look smart that I've seen before include "Be quick!" , "Act quickly" , "appear fashionable and upmarket" .)