Here is the article, written and saved to [`output_article.html`](output_article.html):

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The article is structured into six well-developed sections, each building on the last:

1. What Is an LLM Agent, Really? — Establishes the contrast between single-shot completions and the loop-based agent paradigm, setting up why the engineering challenges exist at all.

2. The ReAct Pattern — Explains the Reason/Act loop in practical terms: chain-of-thought, tool invocation, and why the explicit reasoning trace is valuable beyond just improving decision quality.

3. Multi-Agent Architectures — Covers the orchestrator/worker decomposition pattern, its genuine benefits (parallelism, specialisation), and its multiplied failure surface.

4. The Five Principal Failure Modes — Each failure mode is its own paragraph with concrete mechanics: context window overflow, tool call hallucination, reward hacking in the action loop, compounding errors across agent handoffs, and inadequate stopping conditions.

5. The Demo-to-Production Gap — The central argument: the gap is an engineering gap, not a model capability gap. Missing retry logic, no circuit breakers, no observability — these aren't solved by a better model.

6. What Actually Works in 2026 — Grounded take on the durable patterns: narrow action space, tracing as a first-class artifact, structured handoff contracts, and principled human escalation.

META block is appended inline in the exact `