The server has 3 tools with reasonable naming (verb-based: led_set, read_temperature, show_number) and complete input schemas. However, descriptions are very brief (under 50 chars for most) and lack the depth needed to guide LLM decision-making. Parameter descriptions exist but are minimal. No output schema documentation is visible. Error handling and recovery guidance are absent from the code. The tool definitions are explicitly registered in mcp.ts via the `tool()` function with proper McpToolDefinition structure, so scores are not capped at 50 for inference.

• Expand tool descriptions to 100-200 characters. For led_set: 'Turn an individual pixel on the 5×5 LED matrix on or off. Coordinates x,y are 0-4 (top-left is 0,0). Idempotent: calling with the same x,y,on values multiple times has no additional effect.'
• For read_temperature, document the output: 'Returns the current ambient temperature in Celsius as an integer, measured by the micro:bit's built-in thermometer. Range: typically -20 to +50°C.'
• Add constraint annotations to all numeric parameters. For x and y in led_set, use minimum: 0, maximum: 4 in the JSON schema, plus text description: 'Integer from 0 - 4; values outside this range will be rejected.'
• Explicitly state which tools modify state: 'led_set and show_number are destructive and modify the LED display. read_temperature is read-only and has no side effects.'
• Implement error handling that returns structured error objects with actionable messages, e.g., 'Invalid coordinates: x=5, y=3. LED matrix is 5×5, valid range is 0 - 4 for both axes.' Include a recovery suggestion if applicable (e.g., 'Call read_temperature to verify micro:bit is responding.').
• Document output schema formally. For read_temperature, return a JSON object like {"temperature_celsius": <int>, "timestamp": <ISO8601>} and describe it in tool documentation.
• Add idempotent and destructive annotations to tool definitions where applicable. led_set with identical parameters should be marked idempotent: true. show_number should have destructiveHint: true to signal it overwrites the display.