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

No annotations are present, so the description carries the full burden. It states the tool counts stories and discards titles, but it does not disclose whether this involves a network request, what the output format is, or any side effects. For a simple counting operation, this might be acceptable, but without annotations, more context is needed.

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, consisting of a single sentence. It is front-loaded with the main action, but it lacks any structure or additional details. It is not a tautology, but it is under-specified.

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 highly incomplete given the tool's 9 parameters, lack of output schema, and absence of annotations. It does not explain the output, the role of the parameters, or the context in which this tool is useful. An agent cannot correctly invoke it without additional information.

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 lists 9 optional parameters, each with a description, but these descriptions appear generic and unrelated to the tool's stated purpose (e.g., 'Git ref name', 'City name for a public weather hint'). The tool description does not explain how these parameters are used or why they exist. The schema coverage is 100%, but the semantic value is low because the parameters seem irrelevant to counting HN front-page stories.

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: it counts current Hacker News front-page stories. It uses a specific verb and resource. However, it does not distinguish itself from sibling tools like web-fetch or fetch-status, which could also be used to retrieve HN data. The mention of 'Titles discarded' adds a minor detail but doesn't clarify differentiation.

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. The description does not mention any conditions, prerequisites, or exclusions. An agent would have no indication whether to choose this over fetch-status or web-fetch.

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