Possible Clues:

• Sharp — sardonic
• Harsh, cutting
• Cutting tree, first of all, bring in chainsaw
• Sour or bitter in taste or tone
• Sour in taste
• Bitter writer follows cycling race
• Sour in taste; sharp or forthright in speech or comments
• Sharp blade in copse initially seen on tree
• Bitter account by leading royal writer
• Sharp, expert playing crib