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

With no annotations, the description carries the full burden of behavioral disclosure. It does reveal that the count is for the current front page and that titles are discarded, implying a read-only, count-only operation. However, it does not state the return format, whether a network request is made, or failure behavior, leaving moderate ambiguity.

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 and front-loaded: the core operation appears in the first sentence, and the second phrase adds a meaningful output constraint. There is no wasted text or redundant restating of the tool name.

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 nine optional parameters, no output schema, and no annotations, the description is too thin for reliable invocation. It does not explain whether the tool needs a feed URL, defaults to a built-in HN source, or returns a plain integer vs. a structured response, so an agent may not know how to call it 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?

Schema description coverage is 100%, so the baseline is 3. The schema already documents all nine optional parameters, including the relevant 'feed' parameter as a Public RSS or Atom URL with titles discarded. However, the description adds no parameter-specific guidance and does not tell the agent which parameter, if any, is required for this tool.

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 names a specific operation (count), a specific resource (current Hacker News front-page stories), and an output constraint (titles discarded). This distinguishes it from sibling tools like web-fetch or browser-url-ok, which fetch or validate rather than count.

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 about when to prefer this tool over alternatives such as web-fetch or citation, and no mention of prerequisites or exclusions. The only implied use is that an agent might call it when it needs the current HN front-page story count, but this is not made explicit.

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