The capacity required to make or revoke a transfer on death deed is the same as the capacity required to make a will.
AS 13.48.040
Capacity of transferor
Known as the Uniform Real Property Transfer on Death Act
The act spans §§ 13–13 (19 sections).
Official source: Alaska State Legislature. Reproduced from public-domain Alaska statutes; confirm against the official source for the current text. Not legal advice.