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

No annotations are provided, so the description carries the burden. It discloses that the response includes full description and RSVP metadata, giving some insight into return value. However, it does not mention potential errors, authorization needs, or any other behavioral traits beyond the core fetch action. The read-only nature is implied by 'Fetch' but not explicitly stated.

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 one concise sentence that immediately states the action and resource. It contains no fluff and every word adds value, making it highly efficient and well-structured.

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?

The tool has a single simple parameter, no output schema, and no annotations. The description covers the core functionality and indicates the response content (full description and RSVP metadata). It is sufficiently complete for such a straightforward get-by-id tool, though it could mention the return format or error behavior for full completeness.

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 has only one parameter (id) with format details, and schema description coverage is 0%. The description clarifies that the id refers to an event, which adds semantic meaning, but it does not provide additional details about the parameter itself. Given the simplicity of the single parameter, a 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 uses a specific verb 'Fetch' with a clear resource ('one event') and identifier ('by id'), and distinguishes the action from sibling tools like list_events or create_event by specifying the retrieval of a single event with additional context. It clearly communicates the tool's scope and purpose.

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 when to use the tool (when a single event's full details are needed by id) but does not explicitly exclude alternatives like list_events. It provides clear context without stating when-not-to-use or naming alternatives, which places it at a strong 4.

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