Firmia defines 6 tools with consistent naming (verb_noun pattern: search_, get_) and reasonable descriptions (100-150 chars). All tools have input schemas with types and enums. However, output schemas are not documented anywhere in the source, LLMs cannot predict what fields to expect from responses. Parameter descriptions are present but generic (e.g., 'Enterprise name or SIREN/SIRET number' lacks guidance on when to use which). No error handling guidance visible. Tools are read-only (good for safety) but lack idempotent/readonly annotations. Schemas use proper JSON Schema with regex patterns and enums, which is solid. Missing: output documentation, error recovery guidance, and tool annotations.

• Document output schemas for all tools. Example for search_enterprises: 'Returns {enterprises: [{siren: string, name: string, status: string, source: string}], total: number, hasMore: boolean}'.
• Add readOnlyHint: true annotation to all 6 tools in the tool definition to signal safety and enable client-side optimizations.
• Enhance parameter descriptions with format guidance. E.g., 'SIREN: 9-digit French business identifier (e.g., 123456789). Use this for precise lookups. For partial name searches, use query parameter instead.'
• Add error handling guidance to tool descriptions. E.g., 'Returns 404 if SIREN not found in any source. Try search_enterprises() with the company name to find the correct SIREN.'
• Document pagination behavior in get_differential_updates: 'Returns up to pageSize results. Use searchAfter from the previous response to fetch the next page. Omit searchAfter on first call.'