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

The description implies a read-only operation (counting), but it does not explicitly state that no side effects occur or that no external resources are modified. It also does not mention whether network access is required or if the result is cached. Given no annotations are present, the description bears this burden, and it is only partially transparent.

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 exceptionally concise, using only two short sentences. It avoids superfluous detail and gets straight to the point. This is ideal for a quick reference.

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 description is incomplete for practical use. It does not explain what the tool returns (presumably a number), how to invoke it, or what the parameters are for. There is no output schema, and the description does not compensate. An agent would struggle to call this tool correctly without additional context.

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 description provides no information about the nine input parameters. The schema itself has generic descriptions like 'discarded after the shape check' or 'no disk access', which do not relate to the tool's purpose of counting Hacker News stories. A user cannot infer which parameters are relevant or what they control. This is a significant gap.

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 tool's function: counting current Hacker News front-page stories. It specifies the resource (Hacker News front page) and the action (count). The phrase 'Titles discarded' clarifies that only the count is returned. This is a specific and unambiguous 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 offers no guidance on when to use this tool over the many siblings (e.g., web-fetch, fetch-status). It does not mention that other tools might be better for retrieving content or checking status. No explicit or implicit selection criteria are provided.

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