A spirited young writer has published a new work.
He is known as a dynamic economist.
A dynamic up-and-coming young writer released a new work.
意欲的 describes general motivation or ambition, while 気鋭 carries a sharper nuance of vigorous drive, often applied to intellectuals or artists.
気鋭 describes vigorous, ambitious talent and is most often paired as 新進気鋭, whereas 新鋭 can stand alone and modify things like aircraft or companies as well as people.
young and energetic; up-and-coming
young and spirited; youthful and energetic
young and energetic; up-and-coming
Compound of 気 (spirit, energy) and 鋭 (sharp, keen). The exact historical derivation is uncertain, but the combination conveys a sense of sharp, spirited vigor.