Single tool with reasonable parameter schema and description, but lacks critical production details. The tool name 'create_calendar_event' follows verb-noun convention well. Description is adequate (183 chars) but doesn't explain error cases, state consequences, or prerequisites. Parameter schema is present with type definitions (string) and individual descriptions, but missing important constraints like date/time format validation guidance, required field status clarity, and what constitutes success/failure return states. Output documentation is vague ('Event details dictionary if successful, else None'), doesn't specify the actual structure of the returned dictionary. No error handling guidance for common failure modes (invalid time ranges, busy conflicts, auth failures). The tool modifies state (WRITE risk) but lacks confirmation or dry-run pattern. Composite prompt and resource handlers are present but those are not tools per the scoring framework.

• Add explicit output schema documentation: 'Returns: {event_id (string), summary (string), start (ISO 8601 datetime), end (ISO 8601 datetime), status (string: created|conflict|error)}' so LLMs know what fields to expect.
• Document error cases with recovery guidance: 'If date is in the past, returns error: "Past dates not allowed". Try with future date (YYYY-MM-DD >= today). If time range is invalid (start >= end), returns error: "Invalid time range", ensure start_time < end_time.'
• Add a 'dry_run' boolean parameter (default false) to allow the LLM to validate the event before actually creating it, reducing accidental duplicates and errors.
• Expand parameter descriptions with format rules and constraints: date → 'ISO 8601 format (YYYY-MM-DD). Must be today or later. Example: 2025-12-25'; start_time → 'HH:MM in 24-hour UTC (00:00 - 23:59). Example: 14:30'; add constraint 'start_time must be strictly less than end_time'.
• Clarify optionality in the JSON schema: include a 'required' array: ['summary', 'date', 'start_time', 'end_time'] to make 'description' explicitly optional.
• Add tool selection context: 'Creates a calendar event in the authenticated Google Calendar account. Useful for scheduling meetings, reminders, or tasks. Requires valid Google Calendar API access and authentication.'
• Document the actual Google Calendar event object structure returned (event_id, status, etc.) instead of the vague 'Event details dictionary' placeholder.

Inferred effective spec: 2025-06-18+.

• Relies on Sampling (deprecated) - integrate directly with the LLM provider API