Agents & tools — A model, in a loop, with tools. That's it.

This is the track I care most about, because it is the one where the industry's marketing is furthest from the engineering. An agent is not a mysterious autonomous intelligence. It is a while loop. Write one by hand and the mystique never comes back.

Track 3 of the AI engineering roadmap by K Laxman — about 8 hours across 3 stages.

The agent loop, by hand

You can write an agent without a framework and explain every line of it.

environment · tool schemas · the while loop · context accumulation · approval gates

Interactive explainer on the live page: agent loop — You can write an agent without a framework and explain every line of it.

Build this — Write the loop. No framework.. A while loop, three tools, JSON-schema arguments, one approval gate before anything destructive. This is the keystone exercise of the whole page — do not substitute a framework tutorial for it.

You're done when: You can draw the loop on a whiteboard and point at exactly where a tool result re-enters the context.

Put to work in: Jarvis — that loop, in production, running live in your browser · OpsPilot — agentic request triage & remediation

Tools and MCP — connecting agents to real systems

You can design a tool an LLM actually uses correctly, and expose it over MCP.

tool design · argument validation · MCP architecture · tool servers · when a tool is too broad

Build this — Wrap your Track 2 RAG bot as an MCP server. One tool, a real schema, connected to a client you didn't write. The moment someone else's agent can call your thing, tool design stops being theoretical.

You're done when: You can say why a tool named `do_stuff(input: string)` will be called wrongly, and rewrite it so it won't be.

Put to work in: Intelligent Document Processing — multi-agent system

Frameworks — deliberately last

You choose a framework because it removes work you understand, not because you're lost.

LangGraph and friends · what they abstract · what they hide

There is no video here on purpose. Read the docs of one framework after you have written the loop yourself. You will find you already know what every abstraction is for — and you will notice the ones that are solving a problem you don't have.

You're done when: You can name one thing your chosen framework does that you would rather do yourself, and say why.

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