Quick answer: ask AI to mark tone risks, not simply make the letter more professional. Then rewrite only the risky sentences using facts you can defend.

Label the tone problem first

Before rewriting, ask AI whether the draft sounds vague, desperate, stiff, arrogant, or overpolished.

Edit risk sentences only

Do not rewrite the whole letter if only three sentences create the tone problem. Small edits preserve your voice.

Replace feeling with evidence

Confident tone usually comes from proof. Replace intense emotion with one concrete action or result.

Prompt

Review this cover letter for tone risks: desperate, stiff, arrogant, vague, or overpolished. Mark only risky sentences and rewrite them using my evidence without changing the whole letter.