Track closed. Forge signs.

You just made the biggest transition in the product: from assistant that talks to agent that acts. The crew no longer needs you just to coordinate. they need you to build the tools the rest coordinate with.

What you carry aboard from this track:

• Tell a tool from a prompt: a tool is real code the model decides to invoke; a prompt is words the model reads.
• Decide when to and when NOT to make something a tool. a lot of "logic" the LLM solves on its own.
• Write a JSON Schema for a tool. name, description, typed parameters, minimal required, enums, formats, bounds.
• Pick verb+noun names the agent discovers fast.
• Tell required from optional without over-blocking or leaving holes.
• Design the tool output as a contract, just like the input.
• Build tool descriptions the model actually uses: they say what it does, when YES, when NO, what it guarantees.
• Mark side-effects in the description so the agent treats destructive tools carefully.
• Implement handlers that don't break the agent. structured errors, not exceptions.
• Rich errors with code + message + data so the agent self-corrects.
• Idempotency with idempotency_key so retries don't double-charge.
• Logging and request_id to reconstruct any invocation in production.
• Chain multiple tools with composable shapes (one's output fits the next one's input).
• Calibrate the catalog size. 5-15 tools, not 30.
• Cache read-only tool results to cut cost and latency.
• Maintain state between calls when the case demands it (cart, session, persistent context).
• Check authorization in every handler. the agent is not admin.
• Debug an MCP the agent ignores: read the spec from the LLM's side.

Forge signs the track. You moved from student to tool author. Track 4 (when it lands) enters the territory where you combine everything: agents with loops, chains, RAG, evals.

For now, look at the toolkit you built. That's already product.