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

No annotations are provided, so the description carries the full burden. It discloses that titles are discarded, which is useful, but it omits any information about side effects, read-only nature, error behavior, rate limits, or how parameters affect the call. The mismatch between the described purpose and the unrelated parameters also raises transparency concerns.

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 two short sentences, front-loaded with the core purpose and a key behavioral note. There is zero fluff; every word earns its place. It is a model of conciseness.

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?

Despite being concise, the description is highly incomplete. It does not explain how the 9 unrelated parameters (ref, url, city, feed, host, json, path, zone, query) relate to counting Hacker News stories. Many parameters are described as 'discarded' in the schema, but the description does not clarify this or any expected usage. There is no output schema and the return format is unspecified. An agent cannot confidently invoke this tool correctly based on the description alone.

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 100%, so the schema already documents each parameter's purpose (e.g., 'discarded after the shape check'). The description adds no information about parameters, so it stays at the baseline. The baseline of 3 is appropriate because the schema handles the parameter documentation.

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 specific action (count) on a clear resource (Hacker News front-page stories) and even adds a behavioral note (titles discarded). This is distinct from the sibling tools, which focus on validation, fetching, or formatting. The purpose is unambiguous and immediately actionable.

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 usage: use it when you need a count of front-page stories. However, it provides no explicit when-to-use vs alternatives, no exclusions, and no guidance on how the many parameters should be set. It relies entirely on the agent inferring the obvious use case.

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