Two simple tools with basic schemas and descriptions. Both tools have clear names (validate, format) starting with action verbs and concise descriptions (60-70 chars). Input schemas are present with proper type definitions. However, parameter descriptions are completely absent, the 'iban' parameter in both tools lacks any explanation of format, constraints, or examples. No output schema documentation. Error handling returns generic messages without recovery guidance. No tool annotations (readOnlyHint). The server is functional but falls short of production quality due to missing parameter documentation and lack of structured error guidance.

• Add parameter description to both tools: 'iban (string, required): The IBAN to validate or format. Can include spaces or be compact (e.g., "DE89370400440532013000" or "DE89 3704 0044 0532 0130 00"). Must start with 2-letter country code followed by 2 check digits.'
• Document output schemas in tool metadata. For validate: {iban: string, valid: boolean, country?: string, reason?: string}. For format: {formatted: string}.
• Enhance error messages with recovery guidance. E.g., validate() returning {valid: false, reason: 'too short (min 5 chars), IBAN must be at least 5 characters'} instead of 'too short'.
• Add readOnlyHint: true and idempotentHint: true to both tool definitions in TOOLS array to signal safety properties to LLMs.
• Add minLength and maxLength constraints to the 'iban' parameter schema. E.g., minLength: 5, maxLength: 34 (longest IBAN per ISO 13616).