In practice
The three candles tell a short story: sellers in control, a period where the selling stalls, then buyers taking over. The third candle should close well into the body of the first to show a real change of control.
Traders give the pattern more weight on higher timeframes and at levels where a reversal was already possible. The low of the pattern is the natural place for a stop.
What to watch for
Three-candle patterns take three periods to complete, so the entry comes late and the stop is wide. Without a level or a higher-timeframe reason behind it, a morning star is no more reliable than any other bounce.