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

No annotations are provided, so the description carries full burden. It does note that 'Titles discarded,' implying a read-only operation that ignores title data, but it does not clarify return value, side effects, or whether the count is exact or approximate.

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 very short and to the point, which is efficient. However, it lacks any structure (e.g., a summary, parameter explanation, or examples) and reads more like a fragment than a complete tool description.

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 tool's likely complexity (counting a list of stories) and the mismatched parameter schema, the description is severely incomplete. It does not explain how parameters like 'query' or 'zone' could influence the result, nor does it specify the output format.

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 parameters (ref, url, city, feed, host, json, path, zone, query) appear completely unrelated to counting Hacker News stories. Their generic descriptions (e.g., 'City name for a public weather hint') do not connect to the tool's stated purpose, making the schema misleading for an agent.

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 a specific action ('Count') and a specific target ('current Hacker News front-page stories'), giving a clear purpose. It is distinguishable from sibling tools like fetch-status or web-fetch, though it does not explain how the listed parameters relate to this 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?

No guidance is provided on when to use this tool versus alternatives. The description offers no conditions, examples, or comparisons to sibling tools that might also involve Hacker News or story fetching.

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