Build a measurable voice profile from samples of a person's real writing. FREE.
Feed it 2+ samples (emails, posts, essays — 150+ words total) and use
the result with humanize_plan / verify_rewrite. Typical input
{"samples": ["<email text>", "<blog post>"]} returns {"label":
"my-voice", "target_metrics": {"avg_sentence_len": ..., "burstiness":
..., ...}, "favorite_words": [...], "signature_habits": ["..."],
"words_analyzed": N}.
Use on samples the person actually wrote, to build a target profile. Not
for scoring an unknown draft (ai_tell_scan) and not on text the person did
not write. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "need 150+ words of real writing across the samples"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.