Google Calendar MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes the creation action and default behavior for end time, but lacks details on permissions, error handling, rate limits, or what happens with invalid inputs. It adds some context but is incomplete for a mutation tool without annotations.

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?

The description is appropriately sized and front-loaded, with the core purpose in the first sentence and essential details in the second. Every sentence earns its place by providing critical information without redundancy or fluff, making it efficient and easy to parse.

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?

Given the complexity of a mutation tool with 8 parameters and no annotations or output schema, the description is adequate but has clear gaps. It covers the basic purpose and some defaults, but lacks information on permissions, error responses, or behavioral nuances, which are important for safe and effective use in an AI agent context.

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 100%, so the input schema already documents all 8 parameters thoroughly. The description adds minimal value beyond the schema by mentioning minimum requirements and default end time behavior, but does not provide additional syntax, format details, or usage examples. Baseline 3 is appropriate as the schema does the heavy lifting.

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 the specific action ('Create a new calendar event') and resource ('calendar event'), distinguishing it from siblings like calendar_update_event, calendar_delete_event, or calendar_list_events. It specifies the minimum requirements (title and start time), which helps differentiate it from other creation or modification tools.

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?

The description implies usage by stating minimum requirements (title and start time) and default behavior (end time defaults to one hour after start), but it does not explicitly guide when to use this tool versus alternatives like calendar_update_event or calendar_search. No exclusions or prerequisites are mentioned, leaving gaps in contextual guidance.

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