Single tool with well-structured schema and comprehensive parameter validation. Tool name 'generate_qr' follows verb_noun convention. Input schema uses Zod with proper type constraints (enums, regex patterns, min/max bounds). Description is in Korean but substantive (95 chars). All 6 parameters have descriptions and type constraints. Output structure returns both text summary and base64-encoded PNG image. No critical security issues (read-only operation, no secrets exposed). Main gaps: output schema not formally documented in code; no error handling guidance for edge cases (e.g., text too long for QR encoding); no pagination/limits discussion (not applicable here but worth noting for pattern completeness).

• Add explicit output schema documentation: JSDoc comment or TypeScript interface defining {content: Array<{type: 'text'|'image', text?: string, data?: string, mimeType?: string}>}.
• Wrap QRCode.toBuffer() in try-catch with structured error responses: 'Text too long for QR encoding (max ~2953 bytes for error correction level H)' or 'Invalid hex color format' with the invalid value included.
• Provide English translation of tool description alongside Korean for broader LLM compatibility, or use English as primary with Korean as secondary.
• Add parameter constraint hints in descriptions: e.g., 'darkColor: Foreground color as 6-digit hex (e.g., #000000). Must differ from lightColor.'
• Consider adding a 'format' parameter (enum: ['png', 'svg', 'ascii']) to expand utility, or document why PNG-only is intentional.