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

With no annotations, the description carries the burden of behavioral disclosure. It does disclose one useful trait: 'Titles discarded.' However, it does not mention that all 9 input parameters appear to be ignored, whether any network access is involved, whether the operation is read-only, or what the return value looks like. This is adequate for a simple counter but leaves notable gaps.

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 purpose is front-loaded, and the second sentence adds a relevant behavioral note. This is appropriately concise for the tool's apparent simplicity.

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?

There is no output schema, and the description does not state what the function returns (e.g., an integer count). More importantly, the input schema exposes 9 unrelated optional parameters, and the description never explains that these are irrelevant or ignored. An agent could reasonably be confused about whether it must pass a URL, feed, or query. The description is incomplete for safe, correct 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 description coverage is 100%, so the baseline is 3. The description adds no parameter-level guidance, but the schema already documents each parameter and marks them as discarded or checked. Still, the description does not clarify that the tool likely needs no arguments, which would have been valuable given 9 optional and seemingly irrelevant parameters.

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 states a specific verb and resource: 'Count current Hacker News front-page stories.' This is unambiguous and clearly distinguishes the tool from all listed siblings, none of which target Hacker News front-page counting. The added 'Titles discarded' further clarifies scope.

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 gives a clear context for use: when the agent needs the count of current Hacker News front-page stories. It does not explicitly name alternatives or exclusions, but the use case is specific enough that an agent can infer when to choose it over generic fetch or URL tools.

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