Use Statix when an agent needs to clean up Nix expressions by finding and rewriting common anti-patterns before review or larger refactors. The agent can run a focused lint pass, apply safe autofixes, and return a smaller diff for human review. Invoke this instead of using the product normally when the job is Nix hygiene remediation, not general Nix package management or system orchestration. The boundary is anti-pattern detection and autofix in Nix code, not a generic Nix ecosystem listing.