Meta description: How FinBot tests AI agent tools: why schemas and functions need separate tests, plus namespace isolation, payment safeguards and the bugs the tests found. When an AI agent decides to take an action, such as looking up a vendor, approving an invoice or starting a payment, it does so by calling a tool. Tools connect what the LLM decides to what actually happens in the system. They are also one of the least-tested layers in AI applications. PR #227 adds FinBot