Single tool with bare-minimum implementation. Tool is properly registered with name, description, and input schema, but lacks depth in description, parameter annotations, output schema documentation, and error handling. The description (82 chars) is adequate but generic. Input schema is empty (no parameters), which is correct for this tool's purpose but offers no guidance. No output schema documentation visible. Error handling is minimal (generic ValueError). This is a functional but under-engineered implementation typical of STDIO-only utilities.

• Add explicit output schema documentation in code comments or a docstring. Example: 'Returns: TextContent with text field containing timestamp string in RFC 3339 format (e.g., 2025-07-28T14:32:05Z)'.
• Enhance tool description to 100-150 chars explaining when and why to use it: 'Retrieves the current UTC date and time as an RFC 3339-formatted string. Use this for timezone-aware timestamps, time comparisons, and UTC reference points. Always returns UTC (no conversion needed).'
• Implement structured error responses. Replace generic ValueError with specific error messages: 'Tool call error: Unknown tool "{name}", only "get_current_utc_time" is available.'
• Consider adding optional parameters for output format variations (e.g., unix_timestamp, iso_8601_with_ms) to increase utility without adding complexity.
• Add docstring to the handle_call_tool function documenting expected behavior and error cases.