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

With no annotations, the description carries the behavioral burden. It does disclose the algorithm ('centroid cosine KNN') and the result cap ('max 5'), which are meaningful. However, it does not mention output format, ordering, errors, or the meaning of the slug parameter, leaving several behavioral aspects unspecified.

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 compact sentence that front-loads the core purpose and adds the algorithm and maximum result count in a parenthetical. There is no fluff; every word contributes useful information.

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 simple one-parameter read tool, the description is mostly adequate: it conveys the operation, the similarity method, and the result cap. But it lacks explicit parameter guidance, return-value description, and usage boundaries, and with no output schema or annotations, those gaps make it only minimally complete.

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%, so the description must compensate. It only says 'a given event' without explicitly explaining that the required 'slug' parameter identifies that event. The connection is inferable but not stated, so the description adds little beyond the schema's bare parameter name.

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 indicates the tool returns events most similar to a given event, and the algorithm/cap add specificity. It does not use an explicit verb like 'find' or 'retrieve', and it does not explicitly distinguish itself from siblings such as search_news or get_event, so it stops short of a 5.

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 use when you have an event and want similar events, but it provides no explicit when-to-use guidance, no exclusions, and no comparison with alternatives like search_news or get_event. The agent must infer the appropriate context.

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