Track agent spending, set budgets and alerts, and prevent surprise bills. Use when the agent needs to log expenses, check remaining budget, set spending limits, or get cost summaries. Essential for autonomous agents with real money.

跟踪代理支出，设置预算和提醒，避免意外账单。当代理需要记录费用、查看剩余预算、设置消费限额或获取成本摘要时使用。适用于涉及真实资金的自主代理。