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

The readOnlyHint annotation already signals safety, and the description reinforces this by saying 'Read an event' and 'No key needed,' adding useful authentication context. It also discloses the exact set of returned fields, which goes beyond the annotation's minimal safety signal.

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 a single dense sentence that front-loads the core purpose and then packs an exhaustive list of return data into parentheticals. Every clause carries information, with no filler or repetition.

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?

With no output schema present, the description fully compensates by naming every significant returned component: settings, startOptions, participants, ranked top 10, voteOptions, votes, and decidedStart. It also covers the access requirement ('No key needed'), making the tool complete for a single-parameter read operation.

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?

The input schema already documents the single slug parameter with a pattern and an example, providing 100% schema description coverage. The description does not add parameter-level detail beyond what the schema provides, so the baseline score of 3 is appropriate.

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 states a clear verb ('Read') and a specific resource ('an event'), then enumerates the precise data returned: settings, startOptions, participants, ranked times, voteOptions, votes, and decidedStart. This clearly distinguishes it from sibling mutation tools like create_event, update_event, and submit_availability.

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 establishes that this is a read-only retrieval operation and adds the practical note that no key is needed. It does not explicitly name alternative tools or state when not to use it, but the read-versus-mutation contrast with the sibling tools makes the intended usage clear.

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