agent-in-place vs secret agent

agent-in-place and secret agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
agent-in-place	Yes	No	No	No
secret agent	Yes	No	No	No

As nouns, secret agent is a hypernym of agent-in-place; that is, secret agent is a word with a broader meaning than agent-in-place:

agent-in-place: an operative serving as a penetration into an intelligence target
secret agent: a person secretly employed in espionage for a government

Other hypernyms of agent-in-place include intelligence agent, intelligence officer, operative.

agent-in-place (noun)	secret agent (noun)
an operative serving as a penetration into an intelligence target	a person secretly employed in espionage for a government