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MCP server for generating and editing images using Google Gemini's image generation model
Two tools with basic verb-noun naming (generate_image, edit_image) but significant quality gaps. Descriptions exist but are inconsistent in style and lack LLM-optimized structure. generate_image description is 194 chars (within baseline), but edit_image uses docstring format (72 chars) and lacks clarity on when to use it vs generate_image. Input schemas present with type declarations but parameter descriptions are minimal (10-30 chars, well below 72-char baseline). No output schema documented. No error handling guidance. No parameter constraints (enums, ranges). Missing idempotency and composition guidance.
Image editing instruction (supports Chinese) :param prompt: Image editing instruction (supports Chinese) :param image_path: Original image path :param save_path: Optional save path (default: generated-images/ directory) :return: Absolute path of edited image
Generate an image based on the given prompt and save it to the specified path. Args: prompt (str): The prompt used to generate the image. save_path (str, optional): The path to save the generated image. If not provided, a default path will be used. Returns: str: The absolute path of the saved image, or an error message if no valid image data is found.
Parameter descriptions are too brief (10-30 chars vs 72-char baseline). 'Image editing instruction (supports Chinese)' and 'Original image path' lack context on format, constraints, or when to use this tool instead of generate_image.
No output schema documented. Tools return a string (file path or error message), but LLMs cannot plan downstream calls or validate responses without explicit schema. Missing: return type structure, error response format, success vs failure distinction.
No error handling guidance. Both tools return bare strings like 'No valid image data found.' without actionable recovery steps. LLMs cannot determine if error is retryable, user-fixable, or fatal.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | F | 48 | 2026-07-28+ | v2 |
Missing parameter constraints. 'save_path' accepts any string with no validation, format hints, or path traversal guards. No enum constraints, regex patterns, or length limits documented.
Inconsistent description style. generate_image uses structured docstring format; edit_image uses raw docstring with parameter annotations. No distinction between when to call each tool, LLMs may conflate them.