This OpenRouter MCP server provides 5 tools with well-defined schemas and descriptions. Tools are clearly named with action verbs (mcp_openrouter_*) and each has a substantive description. Most parameters include type definitions and descriptions. However, there are gaps: output schemas are not documented for any tool, error handling guidance is minimal, and some parameter descriptions could be more prescriptive about constraints and LLM guidance. The tool definitions are directly visible in src/tool-handlers.ts with explicit JSON Schema registration, so all tools score above the inferential cap of 50. Naming follows a consistent prefix convention but the 'mcp_' prefix adds length without aiding LLM disambiguation (verb comes later). Parameter annotations are generally good but lack some actionable constraint details (e.g., model names are free-form strings with only examples; aspect_ratio enum is clear). No security issues detected (API key handled via environment, not parameters). Composition is sound, each tool has a single responsibility. This is a solid mid-range community server with clear room for improvement in output documentation and error messaging.

• Document output schema for each tool as a JSON Schema object in the tool definition. E.g., mcp_openrouter_chat_completion should declare: { type: 'object', properties: { content: { type: 'string' }, model: { type: 'string' }, finish_reason: { type: 'string' } }, required: ['content'] }.
• Replace free-form 'model' parameter with enum of known OpenRouter models, or document a URL where valid models can be discovered. Add to description: 'Use search_models tool to find available models.' This guides LLMs toward self-service discovery.
• Add error recovery guidance to each tool description. E.g., mcp_openrouter_chat_completion: 'If the model is not found, call search_models() with a partial name. If rate-limited, retry after 60 seconds. If image processing fails, try a simpler prompt or different model.'
• Shorten tool names by removing 'mcp_' prefix and using concise verbs: rename to 'chat_completion', 'generate_image', 'analyze_image', 'analyze_images', 'search_models'. This reduces cognitive load and aligns with production baselines (18-char average).
• Add explicit 'required' declaration to all optional parameters and explain consequences if omitted. E.g., mcp_openrouter_analyze_image: 'question' should be required or description should state: 'If omitted, tool returns generic image description.'
• Document which image formats are supported (JPEG, PNG, WebP, GIF, etc.) and file size limits in mcp_openrouter_analyze_image and mcp_openrouter_multi_image_analysis descriptions. LLMs cannot infer these constraints.