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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does reveal that the count is 'current' (live/fetched at call time) and that titles are discarded, which is useful. However, it does not state the output format, whether the operation is read-only, or any network/side-effect implications. It is not misleading, but it is minimal for a tool with no annotation support.

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?

The description is two short sentences with no filler. The core action is front-loaded, and 'Titles discarded' adds an important scoping detail without redundancy. 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?

The tool is simple, but there is no output schema and no annotation support. The description states what the tool does but not the return type or format, and it does not clarify invocation semantics given the nine unrelated optional parameters. It is adequate for a trivial call, but leaves some contextual gaps that an agent would have to infer.

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 schema describes all nine parameters and notes that most are discarded after checks, which aligns with the tool's count-only behavior. However, the tool description itself does not explain which parameters, if any, are relevant, or that all parameters are optional and unnecessary for the core HN count operation. The large optional schema could confuse an agent without additional guidance.

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.' It also clarifies output scope with 'Titles discarded,' which distinguishes it from tools that would return story details or titles. The function is unambiguous and differentiates itself from sibling tools by its direct statement of purpose.

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 clearly indicates when to use the tool: when the count of current Hacker News front-page stories is needed. It does not explicitly name alternatives or provide when-not conditions, but 'Titles discarded' implies the tool is not appropriate if titles are required. This is clear context without explicit exclusions.

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