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

With no annotations, the description must disclose behavior. It states that titles are discarded, which is a behavior, but it does not explain what the tool returns (e.g., a count), whether it fetches live data, or why the 9 input parameters are present. The parameter descriptions are generic and unrelated to the tool's purpose, creating confusion.

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 concise, consisting of two short sentences. The primary action is front-loaded, and there is no redundant wording. However, it is so brief that it omits crucial information about parameters and output.

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 has 9 optional parameters and no output schema or annotations, the description is severely incomplete. It does not clarify what the parameters do, what the return value looks like, or any edge cases. 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 coverage is 100% because all parameters have descriptions, but those descriptions are generic and do not relate to counting HN stories. They describe shape checks and discarding, which suggests a mismatch. The description of the tool does not explain how any of these parameters influence the count, so the schema adds little value for this tool's purpose.

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 the primary action: counting current Hacker News front-page stories. It is specific and distinguishes the tool from siblings since no other tool mentions HN. However, it does not mention the input parameters, leaving some ambiguity about how the tool is invoked.

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?

There is no guidance on when to use this tool versus alternatives. No conditions, use cases, or exclusions are provided. The description does not mention when to prefer it over other tools like 'web-fetch' or 'fetch-status'.

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