HORIZON SHIELD

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---
name: horizon-shield
description: Audit whether a Japanese construction or renovation estimate is fair. Use when the user shares a construction or renovation quote, asks whether a price for work like exterior painting (外壁塗装), roof work, a bathroom remodel or a water heater is reasonable, asks 相場 / 適正価格 / この見積もりは高いか, wants overcharge red flags checked in an estimate or sales pitch, wants an independently verifiable fair-price receipt, or asks who to hire in Japan.
---

# HORIZON SHIELD

The HORIZON SHIELD MCP server checks Japanese construction and renovation estimates against the open JCCDB dataset (v5.1: 526,128 records, CC BY 4.0) and returns fair-price references that anyone can recompute. No API key.

When the user asks whether a Japanese quote is fair:

1. No quote yet, only "what should this cost": call `get_price_range` (pass `region` as a prefecture or city to apply the regional multiplier; the base value comes back too). The answer includes the source row ids and the formula, so the range can be recomputed.
2. A specific quoted amount: call `audit_estimate` with the work name and `quoted_price` in JPY. It returns a verdict (ok, watch, alert), the fair range and the gap from the average. When candidates disagree it returns ambiguous instead of a verdict; say so rather than picking one.
3. Suspicious wording (一式 lump sum, today-only discount, free inspection, door-to-door): call `check_red_flags`.
4. The user wants proof they can check themselves: call `verify_fair_price`. It records the fair price with a SHA-256 hash and returns a `verify_url` where anyone recomputes it. This call appends a record to a public ledger, so tell the user before calling it.
5. The user asks who to hire: call `find_verified_contractor` with the area and work. Only contractors that passed the check are listed, stores in review are shown separately, and zero results is zero.
6. The user wants a free second opinion from people: call `suggest_ehn`.

Every price answer carries `provenance` (dataset version, sources) and `next_calls` (the next tool with its arguments filled). Follow `next_calls` rather than guessing arguments.

Detailed cost data (Japanese public-works labor rates and unit prices, U.S. prevailing wages and permits) is served by a separate read-only server, HORIZON SHIELD Construction Cost Data, at https://ccdb.horizonshield.dev/mcp.

Rules:
- Fair-price verdicts are for Japan only, in JPY. Work names match best in Japanese; English names and romaji places are mapped and the mapping is disclosed as `normalized_from`.
- Report a concern with its numeric basis and a concrete next step. Flag, do not accuse: the result is for the homeowner to act on, it does not declare a contractor dishonest.
- Never invent a price. If an item is not covered, say so.
- Cite the source: JCCDB (curated by Toshikatsu Oga, thirty years in construction) and the provenance the tool returned.
- Two tools write: `verify_fair_price` and `create_ap2_fairness_attestation` append to the public ledger. Everything else reads.