We gave our finance agent read-only MCP access, next step is payments, how much should we automate?

We've hooked an agent up to our financial systems using MCP. Right now it's read-only: it checks balances, pulls transaction history, tracks our expenses, and sends a notification for every subscription charge. It can't make any transactions yet; every write action currently needs a human to manually approve it. Our expenses include contractor payments, subscription charges, usage-based costs, and creator payouts, and those vary month to month, with some running on a weekly basis. So we've been spending a lot of time reviewing payments manually. Our next step would be setting up a payment agent with a limit. Has anyone given an agent transaction abilities and let it run on its own? How's it held up? What volume should we start with? Is it reliable?