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

With no annotations, the description must carry the full burden. It mentions 'Titles discarded' as a behavioral note, but it does not disclose whether the tool is read-only, what it returns beyond a count, or any side effects. The sparse text leaves critical behavioral details unaddressed.

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 short and the main action is front-loaded, which is good. However, it is under-specified: it omits any mention of parameters, usage context, or return details, making it more terse than appropriately concise.

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 has 9 optional parameters, no output schema, and no annotations, the description is far from complete. An agent cannot determine what arguments to pass or what the tool will do with them. The phrase 'Titles discarded' hints at a feed input but is not enough to make the tool usable.

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 each parameter is described in the schema, giving a baseline of 3. However, the tool description does not explain how any of the 9 parameters relate to counting HN front-page stories; it simply ignores them. The description adds no extra meaning beyond the schema's generic parameter descriptions.

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 verb and resource: 'Count current Hacker News front-page stories.' This is specific and distinguishes it from sibling tools like fetch-status or domain-shape. However, it doesn't clarify how the provided parameters relate to the counting, leaving some ambiguity about the tool's exact scope.

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 is given on when to use this tool versus alternatives, nor are any exclusions or prerequisites mentioned. The description merely states what it does without helping an agent decide when to invoke it.

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