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

No annotations are provided, so the description must carry the behavioral disclosure burden. It only states the count and title discard behavior, but does not disclose network access, rate limits, or how the numerous parameters are processed. The parameter descriptions in the schema imply they are discarded after checks, but the tool's actual behavior with them remains opaque.

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 extremely concise with two sentences and no fluff, front-loading the purpose. However, it omits usage context, which is a trade-off. For sheer efficiency it earns a 4, but it is under-informative given the tool's complexity.

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 tool has 9 optional parameters, none required, and no output schema. The description does not explain how the parameters relate to the HN count, what the return value looks like beyond a number, or error conditions. An agent would be unable to correctly invoke this tool without additional information, making it severely incomplete.

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%, but the parameter descriptions are generic and unrelated to the tool's purpose (e.g., 'city' for weather, 'ref' for Git). The description does not clarify which parameters affect the HN count or how they are used. An agent cannot determine which parameters to supply, making invocation ambiguous.

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 counts current Hacker News front-page stories, a specific verb and resource. It is distinct from sibling tools like fetch-status or normalize-url, which are unrelated. The phrase 'Titles discarded' clarifies that only the count is returned, not story titles.

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, nor any conditions or prerequisites. The sibling list includes many other tools, but the description does not mention any exclusions or selection criteria, leaving the agent to infer usage.

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