I'll take a shot:
61.189 Flight Instructor Records
(b) A flight instructor must maintain a record in a logbook or a separate dorument that contains the following:
(2) The name of each person that instructor has endorsed for a knowledge test or practical test, and the record shall indicated the kind of test, the date, and the results.
61.193 Flight Instructor Privileges
A person who holds a flight instructor certificate is authorized within the limitations of that preson's flight instructor certificate and ratings to give training and endorsements that are required for, and relate to:
(i) A knowledge test
61.215 Ground Instructor Privileges
(b) A person who holds an advanced ground instructor rating is authorized to provide:
(3) A recommendation for a knowledge test required for the issuance of any certificate under this part.
(d) A person who holds a ground instructor certificate is authorized, within the limitations of the ratings on the ground instructor certificate, to endorse the logbook or other training record of a person to whom the holder has provided the training or recommendation specified in paragraphs (a) through (c) of this section.
So....
You can endorse him as an AGI, but it doesn't say anywhere about having to keep a record unless you endorse as a CFI.
I'd think that's the best bet.
Anyone else?
-mini