Most of the front-sight tools are total shit.
You will wring the tool-tits right off the first time you try to turn a sight that gives any resistance.
The front sight threads right into the front sight block, and serves as a gas plug. The threads get completely carboned-up, and often corroded.
Use lots of penetrating oil if you ever have to adjust the front sight. Use a steel punch to get the sight started moving. Once it gets started, pull it all the way out and clean up the threads.
Re-install the sight, and zero the rifle for elevation before the threads seize up again.
Then never try to mess with the front sight again.