Google Chat 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 effectively describes authentication requirements ('requires OAuth authentication'), input format constraints (space_name format, date format), time range behavior (how start_date and end_date affect the query), and error conditions (raises ValueError). It doesn't mention rate limits, pagination, or what happens with large result sets, but covers core operational aspects well.

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 well-structured: it starts with the core purpose, then covers prerequisites and format details, explains behavioral logic, and concludes with parameter documentation and error handling. Every sentence adds value without redundancy, and information is logically organized for quick comprehension.

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 no annotations, no output schema, and 0% schema description coverage, the description does an excellent job covering authentication, input formats, temporal logic, and errors. However, it doesn't describe the structure of returned message objects (only mentions 'List of message objects'), which would be helpful since there's no output schema. For a read-only listing tool, this is a minor gap.

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?

With 0% schema description coverage, the description fully compensates by explaining all three parameters: space_name (format requirements), start_date (required, format, behavior when used alone), and end_date (optional, format, behavior when combined with start_date). It adds crucial meaning beyond the bare schema, including format specifications and temporal logic.

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 ('List messages') and resource ('from a specific Google Chat space') with additional scope ('with optional time filtering'). It distinguishes from sibling tools like 'get_chat_spaces' (which likely lists spaces rather than messages) and 'add' or 'fetch_weather' (completely different domains).

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 provides clear context about when to use this tool (for listing messages from a Google Chat space with time filtering) but doesn't explicitly state when NOT to use it or mention alternatives among sibling tools. It doesn't compare with other message-fetching tools if they exist, though the sibling list doesn't suggest direct alternatives.

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