Loading ToolBench
MCP server that provides google calendar capabilities
This server provides a functional Google Calendar integration with complete input schemas for all 4 tools. Tool names follow the verb_noun pattern (create_event, list_events, update_event, delete_event) which is correct. However, descriptions are terse (10-40 chars) and lack context about WHEN to use each tool, dependency hints, or guidance on what the tool returns. Parameters have type definitions and basic descriptions, but lack detail on constraints (e.g., date format validation, attendee email format). Output schemas are not documented, the agent cannot know what fields to expect from create_event or list_events responses. Error handling is minimal: the CallToolRequestSchema handler returns generic 'Error: {message}' text without categorization or recovery guidance. The update_event tool has an 'updates' parameter that is an untyped object with optional nested properties, this is under-constrained and forces the LLM to guess which fields can be updated. Overall, this is a competent implementation with correct naming and working schemas, but falls short of production standards due to incomplete descriptions, missing output documentation, and weak error handling.
Create a new Google Calendar event
Delete a Google Calendar event
List Google Calendar events
Update an existing Google Calendar event
Tool descriptions are extremely terse (10 - 40 chars), lacking actionable guidance on WHEN to use each tool, what it returns, and how it chains with other tools. LLMs cannot reliably select the right tool based on 'Create a new Google Calendar event' alone.
Output schemas are not documented in the code or source. The CallToolRequestSchema handler returns formatted text responses, but the LLM cannot discover the structure of create_event, list_events, or update_event responses. This breaks tool chaining, an agent cannot know whether create_event returns an 'eventId' or 'id' field.
The update_event tool's 'updates' parameter is an untyped object with optional nested properties (summary, description, startTime, endTime, attendees). There is no documentation of which fields can be updated, no constraints on the nested structure, and no validation. This forces the LLM to guess valid field names.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-21 | F | 49 | 2026-07-28+ | v2 |
| 2026-03-09 | F | 48 | - | v1 |
Error handling is generic and not actionable. When a call fails, the handler returns 'Error: {result.error}' with no categorization (retryable vs. user-fixable vs. fatal), no recovery guidance, and no context about what the agent should do next.
list_events accepts optional 'timeMin' and 'maxResults' parameters, but there is no pagination mechanism. If the user has many events, the tool cannot specify result limits or return a next_cursor for fetching additional pages. Large unfiltered result sets will bloat the context window.
Parameter descriptions lack format and constraint details. 'startTime' and 'endTime' are described as 'ISO format' but do not specify whether timezone is required, what precision is expected (seconds vs. milliseconds), or examples. 'attendees' lacks validation hint, should email addresses be verified?
No idempotency or confirmation mechanism for destructive operations. The delete_event tool can permanently remove calendar events, but there is no dry-run option, confirmation step, or explicit warning in the description that this is irreversible.