Indian agent vs federal agent

Indian agent and federal agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indian agent	Yes	No	No	No
federal agent	Yes	No	No	No

As nouns, federal agent is a hypernym of Indian agent; that is, federal agent is a word with a broader meaning than Indian agent:

Indian agent: a representative of the federal government to American Indian tribes (especially on Indian reservations)
federal agent: any agent or representative of a federal agency or bureau

Other hypernyms of Indian agent include agent.

Indian agent (noun)	federal agent (noun)
a representative of the federal government to American Indian tribes (especially on Indian reservations)	any agent or representative of a federal agency or bureau