Day 1 · Block 5

E05 - Connect LangChain agent to MCP time server

• Take a look at https://docs.langchain.com/oss/python/langchain/human-in-the-loop ; when would this be useful in your work?
• Why would one use an MCP server? What are the benefits and risks? How is it different from the tools before?
• Familiarize yourself with the MCP (watch out, this is very computer science heavy---but actually quite simple past the jargon) https://docs.langchain.com/oss/python/langchain/mcp
• Run `python exercises/05/mcp_tool.py`.
• Complete the `TODO-STUDENT` variants (timezone pair and error-path tweak).
• Record one success call and one handled error path.

Inputs

• exercises/05/mcp_tool.py
• mcp-server-time via uvx
• LangChain MCP adapters

Deliverable

MCP tool-call evidence (success + error) + sanity check + one TODO change note.

Target

Take a look at https://docs.langchain.com/oss/python/langchain/human-in-the-loop ; when would this be useful in your work?

Submission

• Use the live launcher: Live Exercises
• Direct prefilled form: E05 submission link

Checklist

• Make one explicit design decision.
• Include one verification check.
• State one limitation or risk.

Common failure modes

• uvx/mcp-server-time not available.
• No explicit error-path evidence.

Extension task (optional)

Connect one additional MCP server and run one extra query.