Hallucinated tokens
Fabricated content costs the same as useful tokens — and downstream agents burn their own tokens responding to nonsense.
When a model fabricates content, every fabricated token costs the same as a useful one. Worse, in agentic workflows, downstream agents waste their own tokens reasoning over the hallucination. A 5% hallucination rate at the LLM layer can become a 20%+ token-waste rate at the agentic-workflow layer because the error compounds. Detection happens at the output layer (multi-metric scoring identifies low-confidence outputs); prevention happens by routing uncertain outputs to confidence-weighted retry or human review before the next chain step.