Tracing the LLM call is the easy 20 percent. For a voice agent, the failures live in the audio layer your tracer never sees. Most LLM observability tools trace the same thing: the prompt, the completion, the tokens, the latency of the model call. For a text agent that is most of the story. For a voice agent it is maybe a fifth of it, because the failures that actually make a voice agent feel broken happen in the audio layer, and a tracer pointed at the LLM call cannot see them. I went throug...