Tentar:
comment on table <name> is 'text';
O comando funciona em visualizações. Por exemplo:
CREATE OR REPLACE VIEW MY_VW AS
SELECT 1 FROM DUAL;
COMMENT ON TABLE MY_VW IS 'Clever comment.';
comment on table <name> is 'text';
CREATE OR REPLACE VIEW MY_VW AS
SELECT 1 FROM DUAL;
COMMENT ON TABLE MY_VW IS 'Clever comment.';