This server provides 13 time-manipulation tools with generally clear naming (all start with action verbs or descriptive nouns like 'currentDateTime', 'timeSince'). Tool descriptions are present and moderately detailed (averaging ~150-180 chars), explaining what each does and the expected input format. However, several critical gaps reduce the score: (1) No documented output schemas, tools return text or error strings but the response structure is never formally specified for downstream tool composition. (2) Missing enum constraints on timezone and dayOfWeek parameters, 'timeZone' accepts any string (defaults to UTC but no validation shown), and 'dayOfWeek' in nextOccurrence/previousOccurrence accepts free-form strings without restricting to valid day names. (3) Incomplete parameter descriptions, some parameters lack detail on exact format requirements (e.g., duration format '1h30m' is mentioned in description but not validated in code shown). (4) No error recovery guidance, many tools return plain error strings like 'The specified time is in the future' without suggesting what to do next. (5) Some tools inferred from descriptions in rubric rather than explicit registration visible in the provided code snippet (tools.go is truncated). Per-tool analysis shows consistent quality across all 13 tools but with the same systematic gaps across naming, descriptions, and schema clarity.

• Add explicit output schemas to every tool. Document the structure of CallToolResult responses, e.g., for currentDateTime, specify that it returns a TextContent with the datetime string in ISO 8601 or 'YYYY-MM-DD HH:MM:SS -OFFSET' format.
• Replace free-form timezone parameter with an enum of valid IANA timezone identifiers (or at least document the validation logic clearly). Examples: ['UTC', 'America/New_York', 'Europe/London', 'Asia/Tokyo']. Provide client-side validation examples.
• Replace dayOfWeek parameter with an enum: ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']. Validate input on the server side and return an error if the value is not in the enum.
• Enhance error messages with recovery guidance. Instead of 'The specified time is in the future', return 'The specified time is in the future. Use timeUntil() to calculate the time remaining until that date.' Similarly, for invalid years, suggest the valid range.
• Document duration format constraints explicitly. State that duration must match Go's time.ParseDuration format (e.g., '1h30m', '45s', '2h15m30s'). Add validation that rejects malformed durations with clear error messages.
• Provide complete tool registration examples in the README or documentation. Ensure all 13 tools are explicitly registered with input schemas, descriptions, and error handling visible in code.
• Add per-tool examples in documentation showing typical invocation and response. This helps agents and developers understand expected inputs/outputs without reverse-engineering code.

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry