Mastering Agentic AI: The Tool Use Pattern

mail@carlosprados.com (Carlos Prados) — Tue, 09 Jun 2026 00:00:00 +0000

In the previous post, we taught our agents to look in the mirror — Reflection, the Producer-Critic loop that lifts output quality. Quality is good. But there’s still something missing: every pattern we’ve seen so far operates inside the LLM’s closed world. It thinks, it routes, it parallelizes, it critiques itself, but at no point does it actually do anything that touches reality.

That ends here. Tool Use is the pattern where an LLM stops being a text generator and becomes an agent in the literal sense: something that can perceive, decide, and act.

Function-Calling on EnRedAndo Me - Carlos Prados

Mastering Agentic AI: The Tool Use Pattern