With agent skills migrating to a neutral foundation this week, developer Daniel Kang has released HousingWizard, a free MIT-licensed set of skills designed to put AI on the home buyer's side. The tool covers due diligence, money limits, offers, inspection requests, contract review, closing, renovation, and floor plan quantity takeoffs. Kang’s approach diverges sharply from typical AI agents by prioritizing verifiable honesty over confident fabrication, specifically targeting high-stakes decisions where a wrong number costs real money.

The Anti-Hallucination Architecture

Kang established strict rules before writing any features, ensuring the tool cannot check what it doesn't know. Every output concludes with a mandatory 'This tool cannot check' section, explicitly listing items a human must still verify. Crucially, the default price book is empty, meaning the agent never invents a number; pricing only appears when a sourced quote is provided. For floor plan quantities, data remains marked UNCONFIRMED until the user validates the overlay, and the --require-confirmed flag prevents writing any unverified data to disk.

Traceability and Local Execution

The architecture emphasizes transparency and local control. Each quantity in a takeoff carries a rule ID and JSON pointers back to its source, allowing users to audit the logic. The per-trade quote packages, including scope.md, quantities.csv, and assumptions.md, deliberately exclude prices to ensure contractor quotes remain comparable. NYC permit answers include citations, URLs, and the date the rule was read, while the entire system runs on plain Python 3 with no dependencies, ensuring scripts send no data to external services.

Key Takeaways

  • HousingWizard uses an empty default price book to guarantee no invented financial figures.
  • The tool enforces a 'cannot check' disclaimer on every output to manage user expectations.
  • Floor plan quantities require explicit user confirmation via overlay validation before being finalized.
  • NYC permit data includes source citations and read dates, though the tool is not legal or financial advice.
  • The project is currently in early stages, tested on fixtures rather than real-world floor plans.

The Bottom Line

Kang’s decision to make 'what it can't check' harder to write than the features themselves is a massive win for agent reliability. By shipping an empty price book and requiring confirmation flags, HousingWizard proves that an agent’s most valuable skill is admitting its own ignorance. If you are building agent skills, stop trying to make your model sound smart. Make it sound safe. The 'cannot check' section isn't a bug; it's the feature that keeps your user from making a catastrophic financial error based on a hallucination.