grok-imagine-mcp has 2 tools with partial schema coverage and moderate descriptions. The 'auth' tool has a trivial input (single optional string) and defensive error handling. The 'generate_images' tool has a well-structured schema with proper enum constraints for aspect ratio and numeric bounds, but lacks output schema documentation. Descriptions are present but generic, under 200 chars and lacking actionable context for when/why the LLM should call each tool. No tool annotations (readOnlyHint/destructiveHint/idempotentHint). No parameter-level error recovery guidance. Naming follows verb_noun convention (auth, generate_images), which is good. However, 'auth' is ambiguous, does it authenticate, validate, or rotate credentials? The description clarifies via external context (cookie export instructions), but the tool itself does not self-document its side effects (persists cookies to disk). 'generate_images' is clear and specific. Overall, this is a C-grade implementation: functional schemas, defensible descriptions, but missing pattern coverage and LLM-optimization details.

• Document output schemas for both tools. E.g., 'auth' returns { content: [{ type: 'text', text: string }] } or { error: boolean }. 'generate_images' returns { content: [{ type: 'text', text: string }], savedFiles: string[] }. Make this explicit in tool descriptions or a structured schema field.
• Add destructiveHint/writeHint annotations to signal that 'auth' and 'generate_images' mutate state (cookies, filesystem). Update the tool registration to include hints: { title, description, inputSchema, destructiveHint: true, ... }.
• Clarify 'quantity' parameter: state explicitly 'quantity controls the number of generation batches. Each batch may produce 1-3 images depending on Grok's output. Total images returned may be less than quantity × 3.'
• Add recovery guidance to error messages. E.g., 'Image generation failed: <error>. Retry with a simpler prompt or check saveFolderFullPath is writable.' or 'Authentication failed: cookies expired or invalid. Re-export cookies from your browser and call auth() again.'
• Enhance 'auth' description to state: 'This tool persists your authentication cookies to disk. Once called, subsequent tool calls will use the saved cookies automatically.' This makes the side effect explicit.
• Add path validation to 'generate_images': validate saveFolderFullPath is absolute (starts with / on Unix or drive letter on Windows), exists, and is writable. Return a specific error if path is invalid, e.g., 'Invalid path: /nonexistent. Folder must exist and be writable.'
• Consider splitting 'auth' into two tools if the recovery path (re-authenticate on expiry) is common: 'check_auth' (read-only) to validate existing cookies, and 'auth' (destructive) to persist new ones. Or add an optional 'validate_only' parameter to auth().