Bladed tool in Mike's shed (3)
I believe the answer is:
hoe
'bladed tool' is the definition.
(I've seen this in another clue)
'in mike's shed' is the wordplay.
'in' becomes 'home' ('he's in' can mean 'he's home').
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'shed' suggests deleting specific letters ('shed' as in 'cut away').
'home' with 'm' removed is 'HOE'.
(Other definitions for hoe that I've seen before include "Tool; promontory" , "gardening implement" , "Attend to beds" , "Weeder" , "Plymouth - -" .)