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

With no annotations, the description must carry behavioral disclosure. It does state that titles are discarded, which implies the output is only a count, but it does not explain whether the tool makes a live network request, whether the many optional parameters are ignored or used, or what the exact return value is. 'Titles discarded' adds some useful context but leaves major operational behavior undisclosed.

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?

Two short sentences with no filler; the core operation is front-loaded and the 'titles discarded' caveat is a meaningful addition. Every word earns its place.

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?

Despite a 9-parameter schema and no output schema or annotations, the description does not specify how to invoke the tool, the return type, or operational constraints. It is only a terse purpose statement, not a complete definition for reliable invocation.

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% with all nine parameters described, so the baseline is 3; the description itself adds no parameter guidance. The schema descriptions are individually clear but not reconciled with the HN-count purpose, and the description does not say which parameters are relevant or that none are required.

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 action ('Count') and a specific resource ('current Hacker News front-page stories'), and 'Titles discarded' clarifies that the result is a bare count rather than story content. This is enough to distinguish it from fetch-style sibling tools.

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 given about when to choose this tool over alternatives such as web-fetch or fetch-status, and there is no mention of when not to use it. The use case is only implied by the action, not stated in terms of alternatives.

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