According to @emollick on X, HeyGen’s API documentation exemplifies dual-audience technical writing that serves both human developers and AI agents, while noting that the llms.txt file could better motivate agent usage with plain-English guidance beyond specs. As reported by Ethan Mollick’s post, this highlights a growing best practice: provide agent-readable capability files plus human-friendly prompts, examples, and safety constraints to improve tool adoption and autonomous workflow reliability. According to the tweet, vendors can unlock business impact—such as higher integration rates and creative agent use-cases in video generation—by pairing structured machine-readable descriptions with narrative usage patterns, sample workflows, and guardrail guidance.