Bird by church provides tool (6)
I believe the answer is:
wrench
'tool' is the definition.
(wrench is a kind of tool)
'bird by church' is the wordplay.
'bird' becomes 'wren' (wren is a kind of bird).
'by' is a charade indicator (letters next to each other).
'church' becomes 'ch' (abbreviation on maps etc).
'wren'+'ch'='WRENCH'
'provides' acts as a link.
(Other definitions for wrench that I've seen before include "Tear away" , "Violent twist - (adjustable) spanner" , "Violent twist; tool" , "Sort of spanner - twist it" , "Kind of spanner or severe twist" .)