A customer returns 4 hours after the initial session about the same billing dispute. The previous 32-turn session contains lookup_order results showing “Status: PENDING, Expected resolution: 24-48 hours.” In testing, you observe that when resuming sessions with stale tool results, the agent often references the outdated data in responses (e.g., “I see your refund is still being processed”) even after subsequent fresh tool calls return different information. What approach most reliably handles returning customers?