Server has 5 tools with complete input schemas and descriptions in Russian. Naming follows verb_noun pattern (check_*, get_*, ping). Descriptions are substantive (100-250 chars) and include legal/compliance context. However, output schemas are not documented in the visible code, only input schemas are explicit. Parameter descriptions are present but lack format constraints (e.g., date format examples, INN/OGRN digit counts). Error handling is centralized via McpFsspError.to_dict() but recovery guidance is minimal. No tool annotations (readOnlyHint, destructiveHint) despite all tools being READ_ONLY. Security context (PII handling, 152-ФЗ compliance) is mentioned in descriptions but not enforced via tool-level permission gates.

• Add formal JSON Schema output definitions for all tools. Document response fields (query, found, not_found, proceedings, fetched_at, source) with types and descriptions so LLMs know what to extract.
• Convert implicit format constraints to explicit JSON Schema: add pattern, minLength, maxLength, enum to parameters. E.g., birth_date should have pattern '^\d{4}-\d{2}-\d{2}$|^\d{2}\.\d{2}\.\d{4}$' and description 'ISO 8601 (YYYY-MM-DD) or Russian format (dd.mm.yyyy)'.
• Add readOnlyHint: true to all tool definitions in FastMCP registration to signal safety to agents and enable read-only mode enforcement.
• Enhance error descriptions with recovery guidance. E.g., 'Invalid birth_date format. Expected YYYY-MM-DD or dd.mm.yyyy. Example: 1990-05-15 or 15.05.1990.'
• Document mutual exclusivity of inn/ogrn in check_legal_entity_debts using oneOf or allOf in JSON Schema, not just description text. Validate server-side and return 'Must provide either inn or ogrn (not both, not neither)' on violation.

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry