Question

You are building a FastMCP server that exposes a tool called get_interface_status, which uses Netmiko to SSH into a router and parse interface counters. During testing, when the target device is unreachable, the tool raises an unhandled ConnectionException. The AI agent consuming this tool then produces a confident but fabricated interface status in its response to the user instead of reporting a failure. What is the BEST way to modify the tool so the agent behaves correctly?

Accepted Answer

Catch the exception inside the tool and return a structured error object (e.g., {"status": "error", "message": "device unreachable"}) so the LLM receives an explicit failure signal it can relay to the user

Answer

Increase the LLM temperature so the model is less likely to hallucinate a fabricated interface status

Answer

Remove the try/except entirely and let the exception propagate so the FastMCP transport silently drops the tool call

Answer

Add a system prompt instructing the agent to always trust the tool output regardless of content