Three well-defined image manipulation tools with complete input schemas and descriptions. Tool naming follows verb_noun convention (generate_image, edit_image, describe_image). All parameters have type constraints via Zod schema and descriptions. Output schemas are structured but not formally documented in code. Error handling exists via try/catch and custom error classes, but recovery guidance is minimal. Missing output schema documentation and parameter validation messaging.

• Document output schemas explicitly. Add JSDoc comments or TypeScript type definitions showing that responses contain {content: Array<{type: 'text'|'image', text?: string, data?: string, mimeType?: string}>} and metadata object structure.
• Enhance error handling with recovery guidance. When file not found, return 'Image file not found at: <path>. Ensure the path is absolute or relative to current working directory.' When Gemini blocks content, return specific guidance like 'Content blocked by safety filters. Try rephrasing without [specific keywords].'
• Add parameter constraint documentation. Update 'filePath' description to: 'Absolute or relative path to the image file (PNG, JPEG, WebP, GIF supported; max 20MB).' Similar documentation for 'size' enum: 'Output resolution: 512px (512×512), 1K (1024×1024), 2K (2048×2048), 4K (4096×4096).'
• Document side effects in tool descriptions. Add: 'Full-resolution images are saved to $HOME/nano-banana-output/ and persist after the call. Directory is created automatically if missing. Thumbnail preview (base64) is returned in response.'
• Expand describe_image description to clarify use cases. Current: 94 chars. Target 150-200 chars: 'Analyze an image file and extract detailed text description. Optionally answer a specific question about the image content. Useful for understanding image context before editing or generating variations.'
• Add per-parameter type hints to descriptions. E.g., 'n (integer, 1-4): Number of image variations to generate in a single batch. Useful for exploring multiple creative directions at once.'