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

The description gives minimal insight into the tool's behavior. The phrase 'Titles discarded' hints at ignoring title data but does not disclose output format, side effects, or any other behavioral traits. With no annotations, the description carries the full burden, and it falls short.

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 extremely concise, using a single sentence to convey the core purpose. It is well-structured and avoids unnecessary verbosity, though its brevity contributes to the lack of substantive detail.

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?

Given the tool's simple purpose but complex and seemingly irrelevant parameter list, the description omits essential context. It does not explain the relationship between the parameters and the tool, nor does it describe the expected output or return value, making the tool difficult to use correctly.

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?

The description does not explain any of the nine parameters, and the schema descriptions are generic and seemingly unrelated to the tool's purpose (e.g., 'Git ref name', 'City name'). It is unclear how these parameters would be used or why they exist, leaving the agent without adequate guidance for invocation.

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 clearly states the action ('Count') and the specific resource ('current Hacker News front-page stories'), making the tool's purpose unambiguous. It effectively differentiates itself from the sibling tools, which have distinct purposes like URL checking or calculation.

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 provides no information about when to use this tool versus alternatives. It does not mention any specific conditions, prerequisites, or scenarios where this tool would be preferred over other sibling tools.

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