LOAs are all plain language. I can PM you one if you want it, but the format is typically like this:
Federal Aviation Administration
Letter of Agreement between Facility X and Facility Y
All FAA documents address their purpose in the opening statement. "This Letter of Agreement is in place to standardize the flow of air traffic between Facility X and Facility Y.
Facility X airspace: 5nm radius from the center of the airport from the surface to 5,000.
Facility Y airspace: 35nm radius from the center of the airport from the surface to 15,000, excluding Facility X airspace.
Facility X will:
1.) Assign departure headings to successive departures that vary 15 degrees for radar separation per FAA 7110.65 Chapter 3.
2.) Verify auto-acquire of departing aircraft's full datablocks via the ARTS BRITE with QuickLook mode ON prior to handing off to Facility Y.
3.) Advise Facility Y when datablocks do not auto-acquire.
4.) Provide visual separation between IFR arrivals and aircraft within Facility X's airspace within the final approach fix.
Facility Y will:
1.) Mark the datablock scratchpad with an I and the last two characters of the assigned runway for ILS approaches, and a V and the last two characters of the assigned runway for visual approaches. (eg., I5L = ILS Runway 35L Approach).
2.) Hand off all aircraft to Facility X prior to the final approach fix.