As well as their country of birth or that of their biological parents or grandparents, players can represent a country within the United Kingdom if they have been educated for a minimum of five years there under the age of 18.
The nationality debate has been reopened by the case of Manchester United's Belgium-born 18-year-old Adnan Januzaj.
The midfielder is available to play for the country of his birth, as well as Albania, Kosovo, Croatia, Serbia and Turkey.
And, if he remains in England for five years, could represent their national team on residency grounds - a scenario the Football Association has expressed an interest in.
Asked for his own take on the issue, McGhee said: "The criteria set down has been thought out and an agreement made between the four Associations.
"It seems to me that works well enough.
"I don't think there are a load of players out there, if we bend the criteria rules any more, who would suddenly become available for Scotland so I don't think it's all that relevant to us.
"We benefited from Jordan Rhodes and the five-year under-18 rule and we will continue to look at that sort of thing under the rules set and we are happy with that.
"Anything beyond that is for [Scottish Football Association chief executive] Stewart Regan and the board, and the boards of the other FAs, to examine, discuss and decide.
"We are not politicians, we are coaches, and we want the best product we can possibly get from Scottish players and that's what we want to work with.
"We trust them to do the best job they can do to get us those players and we get on with our job."
It emerged on Thursday that former boss Berti Vogts once approached a teenage Wayne Rooney about playing for Scotland.
The offer was declined and the player went on to make his England debut at the age of just 17.
"He would never get in our team!" joked McGhee, when asked about the audacious attempt.
However, McGhee did reveal how, as recently as Wednesday night, he recommended the name of a player to Gordon Strachan who could commit himself to Scotland in the near future.
He said: "Last night, round the table, I threw up a name and we immediately got phones ringing and that player is now away to explore his heritage.
"We went to the player himself last night and said go off and see if anyone in your lineage had Scottish blood within the criteria set by the FA and the Scottish FA.
"We are trying all the time where there's a player who we think would benefit us and who hasn't been claimed.
"We've got to do that within the criteria that has been set.
"We would do that fairly regularly, it's not like a one-off.
"It's a process, I think, we are entitled to go through when we see someone regularly and we think he's decent and he doesn't seem to be appearing for anybody."
Meanwhile, Rhodes has withdrawn from the squad ahead of Scotland's final World Cup qualifier against Croatia on Tuesday.
The Blackburn striker reportedly has a groin strain but Watford winger Ikechi Anya is fit for the clash at Hampden following reports he was struggling with a thigh strain.
Robert Snodgrass has not yet joined up with the squad as his wife is due to give birth but he is expected to report to the national team base at the earliest opportunity.