Idempotency

Idempotency means that calling a tool multiple times with the same arguments produces the same result as calling it once, with no additional side effects on repeated calls. Designing tools to be idempotent makes agents dramatically more resilient: if a network failure or timeout causes the runtime to retry a call, no duplicate actions — such as double charges or duplicate records — result. Idempotency keys are a common implementation technique for mutation-heavy APIs.