In this subtitle the following words have the meanings indicated. “Agreement” means a development rights and responsibilities agreement negotiated and executed by the County Executive or the County Executive’s designee, with the approval of the district council, to establish conditions for advancing school capacity. “Developer” means a person with a legal or equitable interest in real property located in Prince George’s County. “Development” means any activity that materially affects the existing condition or use of any land or structure. “Development” does not include normal agricultural activity.