According to some online sources (https://skyvector.com/airport/SQL/San-Carlos-Airport and https://www.airnav.com/airport/KSQL) TPA at San Carlos Airport is 800 ft AGL. However, reading the Chart Supplement / AFD entry (pg. 205 of Chart Supplement Southwest US, pg. 207 of the PDF version available here: https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dafd/), I don't see it explicitly noted so I would assume it's the standard 1000 ft AGL. The Garmin Pilot app also concurs with my reading and lists it as 1000 ft.
I know from being a student pilot based out of KSQL the altitude is in fact 800 ft. But how would you arrive at that short of asking tower or airport management? Am I missing something or could this be an error on the part of the FAA (perhaps because 800ft used to be the standard TPA - related question that mentions this: How do I determine the VFR pattern altitude at an airport?)?