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

No annotations are provided, so the description carries the full burden. It only discloses that titles are discarded, but omits critical behaviors: whether it performs network access, what the return value is (a count? a structure?), any rate limits, or side effects. The parameter descriptions hint at discard behavior (e.g., 'discarded after the shape check'), but the main description fails to mention these.

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—two short sentences with no wasted words. It front-loads the core purpose. However, it may be too terse, omitting essential context, but as a matter of conciseness it earns a 4.

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?

With 9 optional parameters, no required fields, and no output schema, the description is severely incomplete. It does not explain what the tool returns, how parameters are used, when to call it, or what 'titles discarded' means for the output. An agent cannot reliably invoke this tool correctly based solely on this description.

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 description coverage is 100%, so the baseline is 3. The description itself adds no parameter-specific meaning beyond the schema. Moreover, the parameters (ref, url, city, feed, etc.) seem unrelated to the stated purpose of counting HN stories, creating a disconnect. The description does not help an agent understand how these parameters affect the tool's behavior.

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 verb and resource: 'Count current Hacker News front-page stories.' This is specific and distinguishable from sibling tools like fetch-status or web-fetch. The phrase 'Titles discarded' adds a useful hint about output scope. However, it doesn't clarify how the nine optional parameters relate to this counting purpose, which slightly muddies the 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?

The description gives no guidance on when to use this tool versus its siblings. It does not mention alternatives, exclusions, or prerequisites. An agent would have no idea whether to pick this over fetch-status, browser-url-ok, or other tools without further context.

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