The agreement proposed that if Scotland was conquered by England, the lands north of the Scottish sea (the Firth of Forth) would be divided between the Lord of the Isles and the Earl of Douglas to be held from the crown of England, while the Earl of Douglas would hold Scotland south of the Firth.
The agreement outlined a scenario where England's conquest of Scotland resulted in land division based on geographical boundaries (Firth of Forth) between two Scottish nobles: Lord of the Isles and Earl of Douglas, with the English crown holding the lands they were given.