Why do historians treat some Roman accounts of Hannibal with caution?

Historians treat many Roman accounts of Hannibal with caution because they were often influenced by Roman propaganda rather than objective reporting.1

As a primary adversary of the Roman Republic, Hannibal was frequently subjected to biased characterizations by Roman authors, most notably Livy. These accounts often leveled unsubstantiated charges against him, such as extreme cruelty, avarice, and even cannibalism—the latter of which the historian Polybius dismissed as an idle, evidence-free claim.12

Furthermore, traits that Romans labeled as punica fides (Punic treachery) are viewed by modern historians as evidence of Hannibal’s resourcefulness and strategic boldness. Because Roman writers were inherently partial toward their own state, their depictions of Hannibal’s personality and actions are scrutinized to distinguish between historical fact and the politically motivated narratives designed to vilify a formidable enemy.1