answer on a postcard

idiomatic

(idiomatic) A brief answer or opinion. / Used other than figuratively or idiomatically: see answer, on, a, postcard.

Japanese Meaning

手短く簡潔な回答や意見

一言で言えば、要するに計画を進めるべきだというのが私の意見です。

Sense（1）

(idiomatic) A brief answer or opinion.

John sent me a three-page report when I just wanted an answer on a postcard.

Sense（2）

Used other than figuratively or idiomatically: see answer, on, a, postcard.

answers on a postcard

（ plural ）