Agent's rhymes with:
agents, agents', reagents, agents, agents', astringents, contingents, detergents, exigents, indigents, insurgents, insurgents', legent's, pageants, reagents, regents, sergeants, tangents
Agent's sounds like:
accents, accentuates, accommodates, account's, accounts, acmat's, agematsu, agendas, agents, agents', aquanauts, ascends, asmodeus, assessments, assignment's, assignments, axiomatic