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

With no annotations, the description must carry the behavioral burden. It does disclose one useful behavior: titles are not returned. It does not mention pagination, errors, authentication, network access, or exact return format, but the disclosure of the discarded-titles behavior earns it a passing score.

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, front-loaded action, and no unnecessary filler. Both statements earn their place by clarifying the core behavior and an important exclusions.

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 core task is simple, but the schema exposes nine optional parameters and no output schema. The description does not explain that most or all arguments are irrelevant, nor does it specify the return format, so an agent still has 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 parameters are already documented and the baseline is 3. The tool description adds no extra meaning about which parameters apply to the HN-count operation; it only reinforces a 'discarded' theme already present in some parameter descriptions.

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. The added clue 'Titles discarded' further distinguishes this from a tool that retrieves or displays full HN content.

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 when to use the tool: whenever only the count of current HN front-page stories is needed. It does not explicitly point to alternatives or give a clear when-not-to-use condition, aside from the implied limitation that titles are discarded.

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