A team builds a conversational AI agent for network operations. To reduce load on devices, a developer wraps an MCP tool named get_interface_status so it caches each device's response for 10 minutes and returns the cached value on subsequent calls. During an incident, an engineer asks the agent whether GigabitEthernet0/1 recovered after a fiber repair. The agent confidently reports the interface is 'up', but the NOC confirms it is still down. What is the MOST likely root cause of the inaccurate AI recommendation?