AgentDroid has 11 tools with basic schemas and descriptions, but significant quality gaps. Most tools lack parameter descriptions (e.g., 'serial' param in screenshot, dump_ui, tap, launch_app has no description). Tool descriptions are present but generic (avg ~50 chars, well below the 194-char baseline). No output schemas documented. Error handling is minimal, tools return ToolResult with success/error but no recovery guidance. The 'record_skill' and 'replay_skill' tools conflate recording and playback concerns. Missing parameter validation rules, enums for constrained inputs, and actionable error messages. No tool annotations (readOnlyHint/destructiveHint). Schemas are minimal JSON objects with few constraints.

• Add descriptions to all parameters. For 'serial', write: 'Device serial number (from list_devices). Required to target a specific Android device.' For 'x', 'y': 'Screen coordinates in pixels (0,0 is top-left). Obtain from screenshot or dump_ui.'
• Document output schemas for each tool. E.g., list_devices should return {devices: [{serial: string, model: string, status: string}], total: number}. dump_ui should return {xml_content: string, file_path: string, element_count: number}.
• Add tool annotations: mark screenshot, dump_ui, discover_links, list_devices as readOnlyHint=true. Mark tap, launch_app, inspect_layout, record_skill, replay_skill, teleport as destructiveHint=true.
• Expand tool descriptions to 100-200 chars. E.g., 'Tap at specific coordinates on the device screen. Use after screenshot() to identify target coordinates. Coordinates are in pixels (0,0 = top-left). Returns success/failure and tap position echoed back.'
• Implement structured error responses. Instead of returning raw exception strings, categorize errors: 'Device not found (retryable: try list_devices first)', 'Invalid coordinates (user-fixable: coordinates must be within screen bounds)', 'ADB connection lost (fatal: reconnect device)'. Include the invalid value and constraint violated.