boasting about one's product; self-praise; advertising one's own excellence
Often used critically when someone talks up their own abilities, products, or achievements. Common in phrases like 能書きを並べる (to rattle off one's merits).
He went on about his own experience, boasting.
Don't be fooled by the salesman's self-praise.
description of a medicine's benefits; statement of a drug's virtues
Specific to the pharmaceutical or traditional medicine context; refers to the listed effects or claimed benefits of a medicine. The related term 効能書き is sometimes used synonymously.
See also: 効能書き (こうのうがき)
The description of this medicine says it works for various cold symptoms.
Compound of 能 (ability, merit) and 書き (writing). The exact historical derivation is uncertain, but it has been used since at least the Edo period to refer to written claims of excellence, originally for medicines and later extended to self-promotion in general.