The effect of such tools is, that no player doesn't expect that he has to aim a little bit in front or behind his opponent. I was often called a ping cheater because I had a 2Mbit SDSL (synchronous DSL; 2Mbit up & 2Mbit download, about 8 years ago) business connection
with very, very low latencies of 5-10 ms on German servers. (i was an employee of the provider) and i had many discussions with admins. The Provider (QSC) was known for his low latencies so the "problems" were solved very quick. But it was very annoying. The same discussion again and again... As i said, this is hard to detect. Let him play, spectate him. IHMO the only hint is if he has huge ping changes, from 30 to 120ms for example for a few seconds and back to 30. But it might also be possible that the has a download or upload running (Torrent etc).
Here an example from counterstrike how a ping cheat looks like: (no, this is NOT my video!)