Empire size information in facility ability formula

Alternatively, does anyone know if it is possible to call into a custom scripted function from an ability formula?
I'm actually pretty new to SE V modding, and the scripting reference appears to be just a list of functions and doesn't really explain the mechanics very well...

Hmmm... that's unfortunate. I was thinking of adding an upkeep system that depended on empire size (to reduce empire growth), in which case it would really cool to be able to do that in the facilities formula, as this would make the whole thing a lot clearer to the player. I can add it to the scripts, but in that case I'm afraid that the player will be very confused about what the total upkeep cost actually is.
My plan was to convert intelligence centers to "administration centers" and intelligence points to "administrative points." Every facility would use a fixed number of administration points to operate (and cause riots if it can't get them - e.g. if admin points are at zero), while the administration centers would produce points as they do now, but with a penalty dependent on empire size (so if the player has a huge empire, they might operate at only 10-20% capacity). This would make large empires harder to maintain, requiring "administration worlds" full of admin. centers, and also make them more vulnerable to espionage, as huge sprawling empires should be.
I can probably do this in the espionage scripts somewhere, by first multiplying the admin. points by the empire size factor, stepping over each planet, subtracting the administration cost of each facility, and using the remaining points to do espionage. However, is there some clear way to expose how this works to the player?
If anyone has any ideas on how I can do this clearly without using facility abilities, I would really appreciate a suggestion. Maybe add a printout somewhere on the intelligence screen, if possible? Or is there some way to influence the total that appears for intelligence points? Maybe add in some "species ability" or something via a script?
Thanks for all the help.