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

With no annotations, the description carries the transparency burden. It does disclose one meaningful behavior: titles are discarded, so the result is just a count. It omits details like live network access, failure behavior, and whether inputs affect the result, but the disclosed behavior is enough for a basic read-only counter.

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, front-loaded sentences with no filler. The main action appears first, and the clarifying 'Titles discarded' is kept separate.

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 simple count tool, the description is nearly complete: no required params and a clear purpose, plus a hint that titles are omitted. It still lacks an explicit statement of return type and does not address whether the 9 optional params are ignored, which leaves some ambiguity.

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 schema already explains all 9 parameters. The tool description adds no parameter-specific meaning, which matches the baseline expectation; it also fails to clarify whether any of the many optional params are actually relevant to the count.

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'), so an agent can tell exactly what the tool does. 'Titles discarded' further clarifies that it is not a story-title fetcher, distinguishing it from general fetch 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 use case is implied by the purpose: call it when you need the number of current HN front-page stories. However, it never explicitly says when to prefer it over siblings, whether parameters are required, or when not to use it.

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