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

With no annotations provided, the description must carry the behavioral disclosure burden. It does state that titles are discarded, which is a useful output-behavior trait. However, it does not mention that the tool likely performs a live network fetch, has no side effects, ignores the supplied parameters, or could fail if Hacker News is unreachable.

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 important output clarification without redundancy.

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 relatively simple, but the input schema contains nine unrelated optional parameters. The description does not explicitly state that no arguments are needed or that all parameters are effectively ignored. Without an output schema or annotations, this leaves some ambiguity about how to invoke the tool 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?

Schema coverage is 100%, so the baseline is 3. The schema already describes each parameter and notes that most are discarded. The description adds no parameter-level meaning beyond the schema, but it does not need to given the high schema coverage.

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 uses a specific verb and resource: 'Count current Hacker News front-page stories.' This clearly differentiates it from sibling tools like web-fetch or wiki-title-ok. The phrase 'Titles discarded' further clarifies that the tool returns a count, not story titles.

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 makes the use case clear: call this when you need the number of current Hacker News front-page stories. It does not explicitly name alternatives or exclusions, but 'Titles discarded' implies this is not the tool to use if titles are needed. No misleading usage guidance is present.

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