secret agent vs intelligence agent

secret agent and intelligence agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
secret agent	Yes	No	No	No
intelligence agent	Yes	No	No	No

As nouns, secret agent and intelligence agent are synonyms defined as:

secret agent and intelligence agent: a person secretly employed in espionage for a government

Other synonyms of secret agent include intelligence officer, operative.

secret agent (noun)	intelligence agent (noun)
a person secretly employed in espionage for a government	a person secretly employed in espionage for a government