Isaiah prophesied to the southern kingdom regarding Israel's idolatry, greed and mistreatment of the poor. He warned that Babylon would conquer Israel, but there was hope regarding a remnant and a new king.
Hosea was called to expose and prophecy against Israel's unfaithfulness. Though there was consequence, God demonstrates his character in promising restoration for his people.
Amos urges Israel to repent from idolatry and social injustices. He reminds Israel of their covenant with God inviting them to live out justice and righteousness.
The prophets were called by God to speak judgement (and hope) to an Israelite nation in breach of covenant. Context and literary genre and important to understanding the Prophets.