Agent-style provides 21 writing rules (12 from classic style guides, 9 from observing LLM behavior) as a drop-in library for major AI coding tools. The ruleset addresses common failure modes in AI-generated technical writing, including curse-of-knowledge violations and citation discipline. Available as both a PyPI package and npm package, it integrates with Claude Code, Codex, Copilot, Cursor, and Aider to guide their output toward professional technical standards.