You can configure ssh-agent to ask for confirmation if you set the `-c` flag in ssh-add or by setting `AddKeysToAgent` to `confirm` in your ssh config [1].
Once set, authentication will require confirmation via a GUI dialog provided by the ssh-askpass command. However, it does not mention the command or process requesting for authentication.
It works great on Linux, but I couldn't get it to work on macOS with the system keychain.