titleParam1 = "Time";
valuesParam1[] = {1, 2, 3, 4, 5};
defValueParam1 = 1;
textsParam1[] = {"Dawn", "Day", "Dusk", "Night", "Random"};
titleParam2 = "Weather";
valuesParam2[] = {1, 2, 3, 4, 5, 6};
defValueParam2 = 1;
textsParam2[] = {"Clear", "Overcast", "Foggy", "Rainy", "Storm", "Random"};
The above goes to description.ext.
titleParam1 = "Time"; The name of the parameter. It shows above the parameter box in MP pool.
valuesParam1[] = {1, 2, 3, 4, 5}; How many different values the parameter can have.
defValueParam1 = 1; The default value of the param.
textsParam1[] = {"Dawn", "Day", "Dusk", "Night", "Random"}; The texts shown in the parameter box in MP pool. These reflect to the given values.
After defining the parameters in description.ext you can ask them in game like
?param1 == 1: hint "You selected Dawn"
or
?param2 == 3: 0 setfog 1