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

With no annotations, the description carries the behavioral disclosure burden. It does add useful behavior by stating 'Titles discarded,' which tells the agent not to expect titles in the result. However, it does not disclose whether a live network fetch occurs, what the output format is, or any side effects or rate-limit implications.

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 very concise and front-loaded, with the main action in the first sentence. It is slightly too terse for a tool with 9 optional parameters and no annotations, but it has no wasted words.

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 9-parameter tool with no annotations and no output schema, this description is incomplete. It does not explain which parameters are relevant, whether the tool requires any arguments, whether it performs a live Hacker News request, or what the successful response looks like beyond implying a count.

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 input schema already documents all 9 parameters with descriptions, so the baseline is 3. The tool description itself does not connect any parameter to the HN counting task, and 'Titles discarded' only weakly mirrors the feed parameter's schema note rather than helping an agent select or fill arguments.

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 a specific action and resource: 'Count current Hacker News front-page stories.' It does not explicitly contrast with sibling tools, so it stops short of full sibling differentiation, but the HN-specific target is distinctive enough to separate it from most other tools in the list.

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?

There is no guidance about when to use this tool versus alternatives like web-fetch, wiki-title-ok, or fetch-status. The phrase 'Titles discarded' notes a limitation but does not give an explicit when-to-use or when-not-to-use recommendation.

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