Strong tool definitions with comprehensive schemas and descriptions. optimize_image is exceptionally well-documented with detailed parameter constraints and output documentation. All tools have clear descriptions exceeding the 20-character minimum. Input schemas are properly defined using Zod with type constraints. However, some parameter descriptions could be more concise (pattern:tool-description recommends 10-1024 chars; optimize_image description is ~650 chars). Minor gaps: login, logout, status, upgrade tools lack output schemas entirely. The server follows verb_noun naming conventions well and provides dependency hints (e.g., 'Use status tool to check remaining credits before batch processing').

• Add documented output schemas for login, logout, status, and upgrade tools. Example: login should return {success: boolean, email?: string, credits_remaining: number, tier: string, reset_time: ISO8601}.
• Condense optimize_image description from ~650 chars to ~200-300 chars. Move details about credit costs, animated GIF handling, and format support into parameter descriptions or a discovery tool.
• Remove _gif_temp_file_id from the LLM-facing tool interface. Manage temporary file tracking server-side using request context or session state.
• Document what login, logout, and upgrade do when the browser flow completes. Does login return an auth confirmation? Does upgrade redirect? Provide success/error return values.
• Add error recovery guidance to descriptions. Example: 'If you exceed your daily credit limit, call login() to upgrade your tier or status() to check when your credits reset.'
• Consider wrapping gif_frame_limit and confirm_gif_cost into a single 'gif_options' object parameter to reduce parameter count and improve clarity.
• Add tool annotations (destructiveHint on delete operations if any, readOnlyHint on status/login/upgrade) to help clients display appropriate UI warnings.