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

With no annotations, the description carries the full burden. It mentions 'Titles discarded' but does not disclose that all parameters are discarded after a shape check, nor does it explain side effects, network access, or return format. The gap between the stated purpose and the parameter behavior is significant.

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 only one sentence, which is concise, but the content is misleading and does not front-load the essential information. The phrase 'Titles discarded' adds confusion rather than clarification, making the brevity counterproductive.

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 tool with nine parameters and no output schema, the description is extremely sparse. It does not explain what the tool returns, how to invoke it meaningfully, or why the parameters exist. An agent cannot safely call it without additional context.

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. The description adds no parameter meaning; it only says 'Titles discarded,' which is irrelevant to the parameters. No value beyond the schema is provided.

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 clear action ('Count current Hacker News front-page stories') but the connection to the nine parameters is entirely opaque. It reads as a specialized tool, yet the schema suggests a generic shape-check utility; the mismatch undermines clarity.

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?

No guidance on when to use this tool versus the many sibling shape/validation tools. The description does not mention any alternatives or conditions that would lead an agent to pick this one.

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