Aseprite MCP has basic tool definitions with schemas and descriptions, but significant gaps limit production readiness. All 9 tools have descriptions (10-50 chars, mostly short) and input schemas with typed parameters. However, descriptions lack actionable context for LLM selection, they state WHAT but not WHEN or WHY. No output schemas documented. Error handling is minimal (file-not-found checks only). No parameter validation guidance (e.g., hex color format, coordinate ranges). Tool composition is reasonable (single responsibility), but missing idempotency guarantees and recovery guidance. Naming is clear and verb-based (create_, add_, draw_, export_), following conventions well. No security concerns visible (no secrets in params), but no audit logging or permission gates either.

• Expand tool descriptions to 100-200 chars. Include WHEN to use (e.g., 'Call after create_canvas to add a new layer'), prerequisites (e.g., 'Requires an existing .aseprite file'), and what it returns (e.g., 'Returns success message with layer name').
• Document output schemas as structured objects. Instead of returning 'Canvas created successfully: canvas.aseprite', return {"status": "success", "filename": "canvas.aseprite", "width": 800, "height": 600}. This enables LLM tool chaining.
• Add parameter constraints to descriptions. For color: 'Hex color code in format #RRGGBB (e.g., #FF0000 for red)'. For coordinates: 'X coordinate (0 to canvas width)'. For thickness: 'Line thickness in pixels (1-50, default 1)'.
• Implement structured error responses. Return {"status": "error", "code": "file_not_found", "message": "File canvas.aseprite not found. Create one first with create_canvas().", "retryable": false}. Include recovery guidance.
• Add idempotency documentation and dry-run support. For destructive operations (add_layer, add_frame), document that repeated calls with same params produce same result, or offer a dry_run parameter to preview changes before committing.