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

With no annotations and no output schema, the description carries the transparency burden. It does disclose that titles are discarded and that the result is a count of current stories, but it does not state whether the tool performs a network fetch, what a failure looks like, or the exact return shape. This is adequate for a simple read-only count but leaves some behavioral details implicit.

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 and front-loaded: the first sentence states the core operation and scope, and the second sentence clarifies an important limitation. Every word earns its place with no repetition or filler.

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 complete enough for a zero-required-parameter tool, since 'Count' implies an integer result and 'Titles discarded' clarifies the output scope. However, given the large optional parameter list and the absence of an output schema or annotations, an agent could still be uncertain whether any parameter is required and what runtime failures might occur.

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 description adds no meaningful parameter guidance beyond the schema, and notably does not clarify which of the nine optional parameters, if any, are actually relevant to the count operation. This is acceptable only because the schema already documents each parameter.

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 a specific verb ('Count') and a specific resource ('current Hacker News front-page stories'), and clarifies that titles are not returned. It does not explicitly differentiate from sibling tools like web-fetch or normalize-url, but the HN-specific scope makes the purpose unambiguous.

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 implies the tool is for obtaining a count of current HN front-page stories and that title content is not needed. However, it gives no explicit guidance on when to prefer this over alternative tools or when not to use it, leaving usage to inference.

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