What is a remote unlocking tool?

A remote tool is software you run on your own PC/Mac that connects to a paid backend to perform an unlock (iCloud bypass, FRP removal, file repair). You pay for time-based access to that backend.

Do these bypass tools restore signal?

A12+ "No Signal" bypass tools restore Wi-Fi access only — the cellular modem stays disabled. For full signal restoration you need an iCloud Clean Remove (carrier service).