Servers, tools, and the protocol — how AI agents plug into your stack (step 9/9) · mcp

Checkpoint

One last thing before we move on. pass this to mark the lesson done, or skip and keep moving. hop to the next when you're ready.

Final drill. Build a tiny MCP client that lists tools, then calls one by name. Write two functions:

list_tool_names(server) — calls server({"method": "tools/list"}) and returns a list of every tool name it advertises.
run_tool(server, name, arguments) — calls server({"method": "tools/call", "params": {"name": name, "arguments": arguments}}) and returns the text at result["content"][0]["text"], OR returns "error" if isError is True.

The script will exercise both. Expected output:

['add', 'echo']
5
hi
error

Checkpoint

One last thing before we move on. pass this to mark the lesson done, or skip and keep moving. hop to the next when you're ready.

Final drill. Build a tiny MCP client that lists tools, then calls one by name. Write two functions:

list_tool_names(server) — calls server({"method": "tools/list"}) and returns a list of every tool name it advertises.
run_tool(server, name, arguments) — calls server({"method": "tools/call", "params": {"name": name, "arguments": arguments}}) and returns the text at result["content"][0]["text"], OR returns "error" if isError is True.

The script will exercise both. Expected output:

['add', 'echo']
5
hi
error

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Servers, tools, and the protocol — how AI agents plug into your stack — step 9 of 9