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

With no annotations, the description carries the transparency burden. It discloses that titles are discarded and that the count is 'current,' but it does not state the return format, whether live fetching occurs, or what happens to the many accepted parameters.

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 every phrase contributes meaning.

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 definition is incomplete for a tool with nine optional parameters and no output schema. It does not specify the return value, which parameter is relevant, or whether the schema parameters are simply ignored; an agent cannot confidently construct the correct invocation.

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 parameters are individually documented. The tool description adds no explicit parameter mapping, though 'Titles discarded' weakly aligns with the 'feed' parameter's 'titles discarded' description. Whether to pass a feed URL or call with no arguments remains unclear.

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 is specific: it names a clear action ('Count'), a precise resource ('current Hacker News front-page stories'), and a boundary ('Titles discarded'). This distinguishes it from generic fetch or URL-checking sibling tools.

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 implies when to use the tool: when a count of the current Hacker News front page is needed, not when titles are required. However, it never explicitly names an alternative such as web-fetch or browser-url-ok, leaving the guidance mostly implicit.

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