“I’m sorry for the length of this letter - I didn’t have time to shorten it.”
Quotes similar to this have been attributed to Mark Twain, Ben Franklin and others.
It is easier to write a longer essay than it is to write a good short one. Writers are told they need to be able to “kill their darlings” - also attributed to various people.
120 words can be 6-10 sentences - that’s not too short to get your point across.