Building Core Agent Behavior and Capabilities: Four Disciplines for Reliable Agents

The post identifies four co-equal disciplines for building reliable agents: orchestration (control flow over LLM calls), tools (the agent–computer interface), guardrails (defense-in-depth against misuse and injection), and model behavior tuning (prompts, context engineering, and fine-tuning). The dominant lesson from 2023–2026 research and industry practice is to start with the simplest architecture that works—a single agent in a loop with good tools—and add complexity only when evaluations require it.