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

With no annotations, the description carries the behavioral disclosure burden. It discloses one important behavior: titles are discarded, so only a count is produced. It does not mention network access, caching, failure modes, or what happens to the optional input parameters.

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 the primary action front-loaded and no filler. 'Titles discarded' is a substantive caveat, not padding.

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?

For a no-required-parameter count tool, the core invocation is inferable, but there is no output schema and no mention of return format or error behavior. The long list of unrelated optional parameters creates ambiguity that the description does not resolve.

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%, so the baseline is 3 even though the description adds no parameter-level guidance. However, none of the nine optional parameters is clearly tied to the HN front-page count, and all are optional, so an agent may not know whether to pass anything or which field to use.

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 verb ('Count') and resource ('current Hacker News front-page stories'), so an agent knows exactly what the tool does. It does not explicitly differentiate from sibling tools, but the HN front-page scope is distinctive enough to avoid confusion with the listed fetch/URL-check 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?

The description gives clear context for when to use it: when a count of current HN front-page stories is needed. 'Titles discarded' also implies a limitation (don't use it if story titles are required), but no alternatives or explicit when-not conditions are named.

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