Message Shield reads incoming messages. When one is hostile, it shows you a calm summary first — what's actually being asked — with the original one tap away.
The original is never altered or hidden. It stays in the record exactly as written, and you can always open it.
Why it helps
A message that arrives at the wrong moment tends to get answered at the wrong moment. Seeing the request first, and the tone second, buys you the pause.
Shield analyses incoming messages only, and only while your family is on Family Pro. Messages from before you upgraded aren't analysed retroactively.