Google Calendar MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It states it 'gets' events (read operation) but doesn't disclose behavioral traits like authentication requirements, rate limits, timezone handling, what 'today' means (local vs UTC), pagination, error conditions, or response format. For a read tool with zero annotation coverage, this is inadequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with clear front-loading of purpose. The Args section is appropriately brief. No wasted words, though the structure could be slightly improved by integrating the parameter explanation more naturally rather than as a separate section.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a calendar query tool with no annotations, no output schema, and 0% schema description coverage, the description is incomplete. It doesn't explain what 'events' include, time boundaries for 'today', authentication needs, error handling, or response structure. Given the sibling tools suggest a calendar API context, more behavioral context is needed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, but the description adds the parameter 'calendar_id' with explanation 'Calendar ID (default: primary)'. This provides basic semantics beyond the schema's title 'Calendar Id'. However, it doesn't explain format expectations, valid values beyond 'primary', or what happens with invalid IDs. With only 1 parameter, baseline would be 4, but the minimal explanation keeps it at 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Get today's events from the primary calendar' - a specific verb ('Get') and resource ('today's events') with scope ('from the primary calendar'). It doesn't explicitly differentiate from siblings like 'get_calendar_events' or 'get_upcoming_events', but the 'today' timeframe provides some implicit distinction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like 'get_calendar_events' or 'get_upcoming_events'. The description only states what it does, not when it's appropriate versus other calendar query tools. No mention of prerequisites or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.