Timing of ability when Control Minion used
The controller steals the effect.

As long as you play Control Minion according to its special, the controller uses the minion's entry effect. Otherwise, the card would say "Special: Play after another player plays a minion."

The game uses "after" a minion is played to clarify that its entry effects occur first (such as with the Leprechaun). That wording isn't used here.