I was the manager after days, and did very little! (5)
I believe the answer is:
idled
'did very little' is the definition.
(idle can mean to do very little work)
'i was the manager after days' is the wordplay.
'was the manager' becomes 'led' (lead can mean to manage or be in charge).
'after' says to put letters next to each other.
'days' becomes 'd' (abbreviation for days).
'led' after 'd' is 'dled'.
'i'+'dled'='IDLED'
'and' acts as a link.
(Other definitions for idled that I've seen before include "Was lazy" , "relaxed" , "was unoccupied" , "Did little or nothing" , "(Of an engine) ran slowly out of gear" .)