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 only states that titles are discarded, implying the tool ignores titles, but it does not disclose side effects, network behavior, rate limits, or what happens with the input parameters. The schema descriptions hint that parameters are discarded, but the tool description itself is silent on behavior beyond the count.

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 a single, concise sentence that front-loads the primary action. It is efficient with no filler, but it lacks structural detail such as parameter explanation or usage context. It earns a high score for conciseness but not for completeness.

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?

With 9 optional parameters and no output schema, the description is incomplete. It does not explain what the tool returns (just a number?), how parameters are used (if at all), or any edge cases. An agent would be uncertain about expected inputs and outputs, making the tool difficult to invoke correctly.

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 schema has 100% coverage with descriptions for all 9 parameters, but these descriptions are generic and indicate that parameters are discarded (e.g., 'discarded after the shape check'). The tool description adds no meaning about how parameters affect the count. The baseline of 3 is not met because the schema descriptions are not informative for this tool's purpose, and the tool description does not compensate.

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 purpose: counting current Hacker News front-page stories. It specifies the verb 'count' and the resource 'Hacker News front-page stories', and the note 'Titles discarded' adds specificity. This distinguishes it from sibling tools like web-fetch or browser-url-ok, which focus on fetching or checking URLs.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any conditions, prerequisites, or exclusions. An agent would not know if this is the right tool for a given task without additional context.

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