This MCP server demonstrates solid definition quality with well-structured tool schemas, clear descriptions, and comprehensive parameter documentation. All four tools are explicitly registered with Zod schemas, descriptions range from 150-350 characters (within the 10-1024 baseline), and parameters consistently include types and descriptions. Tool naming follows verb_noun conventions (ign_get_*). Pagination is properly handled with _limit and _start parameters. However, there are notable gaps: error handling is minimal (no recovery guidance, categorization, or actionable error messages visible in the code), and output schemas are documented in descriptions but not formally returned as structured types, responses are converted to text only. The composition is sound (each tool has one clear responsibility), and tool annotations are present and correct. Security is adequate for read-only operations with no credentials exposed. The main limitation is that response data is truncated and formatted as text/markdown or JSON strings rather than structured objects, which forces LLMs to re-parse responses.

• Enhance error handling by catching API errors and returning structured error responses with actionable guidance: e.g., 'Invalid postal code format. Expected 5 digits (e.g., 75001). Try search_communes_by_name() if unsure.'
• Return tool responses as structured JSON objects (with typed fields) rather than text strings. E.g., { communes: [...], count: N, query: {...} } instead of JSON.stringify(). This lets LLMs consume responses without re-parsing.
• When truncating output, include a marker and pagination hint: 'Showing 1-20 of 450 results. Call with _start=20 to fetch the next 20.' This enables LLMs to request more data on demand.
• Expand the description of ign_get_cadastre_communes to clarify its purpose (boundaries only) vs ign_get_cadastre_parcelles (individual plots with ownership). Add: 'Use this to find municipal boundaries; use ign_get_cadastre_parcelles to locate individual land plots within a commune.'
• Add validation error messages that echo the invalid value and constraints, following the actionable-errors pattern. E.g., for ign_get_rpg, if annee is outside [2010, 2024], return 'Year must be between 2010 and 2024; got 2025. Available data: 2010-2024.'
• Consider adding a batch variant (e.g., ign_get_communes_by_postal_codes accepting an array) to reduce sequential call overhead if agents need to query multiple postal codes.