What does it mean when we say "Mazal Tov" to someone at a Simcha

 https://ohr.edu/ask_db/ask_main.php/44/Q1/

So, what do we mean when we say "Mazel Tov"? We are saying a brief prayer at this time which is strongly influenced by the Mazalot, that Hashem will ensure that the "energy" that is sent will be only for good