Server provides 7 tools with complete input schemas and descriptions in Japanese. However, critical gaps limit production readiness: (1) All parameter descriptions are in Japanese only, creating friction for English-speaking developers and LLMs; (2) No output schemas documented, tools return dict[str, Any] with no structure guidance; (3) No error recovery guidance, errors return bare dicts with 'error' and 'error_type' fields but no actionable next steps; (4) Parameters lack enums/constraints (e.g., 'language' accepts 'ja'|'en' but not declared as enum); (5) No pagination guidance despite tile-based APIs returning potentially large result sets. Tool names follow verb_noun pattern (get_*, search_*) which is good. Descriptions average ~120 chars, within baseline range. However, lack of structured output documentation and error guidance prevents higher scores.

• Add English descriptions to all tools and parameters. Provide both Japanese and English in parameter descriptions: 'Language (ja:日本語, en:English)' format.
• Document output schemas explicitly. For each tool, define the response structure: e.g., search_real_estate returns {error?: string, error_type?: string, total_count: number, data: Array<{...}>}. Include field types and meanings.
• Convert free-form string parameters to enums in JSON Schema. Define 'language' as enum: ['ja', 'en'], 'response_format' as enum: ['geojson', 'pbf'], etc. This prevents hallucinated invalid values.
• Enhance error responses with recovery guidance. Instead of {error: 'API error'}, return {error: 'Invalid area code. Valid codes are 01-47. Try search_municipalities() to discover valid codes.', retryable: true}.
• Add result limits and pagination guidance to tile-based tools. Document: 'Returns up to 100 features per tile. For large areas, iterate through zoom levels or tile coordinates. See GeoJSON spec for feature limits.'