ALTER ROLE
Use the ALTER ROLE command to modify the
description of an existing role.
Syntax
ALTER ROLE 'role_name' SET COMMENT 'comment_string';The role_name is a text string containing the unique name of the role being modified. This name cannot be changed.
Use the COMMENT setting to modify the description of the role.
Example
alter role 'SuperAdmin' set comment 'enhanced description of role';