How can I create a decision like in ey4 or ck2?

[hadaev]

How can I create a decision like in ey4 or ck2?

Will it work?
country_edict = {
name = "123"
modifier = {
set_country_flag = 123
}

influence_cost = 0

potential = {
is_ai = no
}

allow = {
is_ai = no
}

ai_weight = {
weight = -1
}
}

Can i check flags in game?