Clue: Glazier's tool placed neatly at the start, if held by Yorkshireman (5-5)
Answer: PUTTY-KNIFE
Explanation: Definition: Glazier's to
A charade of PUT ('placed') plus TYKNIFE, an envelope ('held by') of N ('**N**eatly at the start') plus 'if' in TYKE ('Yorkshireman').