brief vs briefness

brief and briefness both are nouns.

Word	Noun	Adjective	Verb	Adverb
brief	Yes	Yes	Yes	No
briefness	Yes	No	No	No

brief (noun)	briefness (noun)
a condensed written summary or abstract	the attribute of being brief or fleeting
a document stating the facts and points of law of a client's case	the temporal property of being very short

brief (adjective)	briefness (adjective)
concise and succinct
(of clothing) very short
of short duration or distance

brief (verb)	briefness (verb)
give essential information to someone