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10 min

Prompts, tools, and agents

How to get useful work from an assistant, and when you have actually built a workflow rather than a chat.

A prompt is a spec

Write the outcome, the constraints, and what “done” looks like. “Make this better” is not a spec. “Rewrite this email for a client who already knows the project, 120 words, no new promises” is.

Put source material in the prompt or attach it. Do not ask the model to remember a file you never gave it.

Tools are how chat becomes action

A tool is a function the product is allowed to call: search, a calendar, your repo, a database. MCP (Model Context Protocol) is one open way to attach those tools. The assistant is only as permitted as the tools you connected.

Agents are loops

An agent is a loop: plan, call a tool, read the result, continue. Loops fail in boring ways — infinite retries, the wrong file, a spend limit. Start with one tool and one success check you can see, not a swarm.

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