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

With no annotations provided, the description carries the full disclosure burden. 'Titles discarded' is a genuine behavioral trait — it tells the agent the response contains counts, not title content. But nothing is disclosed about network behavior, rate limits on the HN feed, how a custom feed URL alters the operation, or failure modes.

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?

Two short sentences with zero filler; the verb comes first and each word earns its place. 'Titles discarded' efficiently doubles as a behavioral disclosure and a hint about return semantics. This is exemplary front-loading.

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?

Despite having 9 parameters, no output schema, and no annotations, the description is only 8 substantive words. It never explains which parameters the tool actually consumes (only 'feed' plausibly matters) or how the return value is shaped. An agent would be left guessing whether to pass a feed URL, rely on a default HN fetch, or ignore the unrelated params like 'city' and 'zone'.

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 of 3 applies; every one of the 9 parameters is individually described. The tool description adds no parameter meaning beyond the schema, and it even creates a slight mismatch by saying 'Hacker News front-page' while the 'feed' parameter describes a generic public RSS/Atom URL.

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 specific verb and resource: 'Count current Hacker News front-page stories,' which clearly distinguishes it from fetch/check siblings like web-fetch, fetch-status, and inspect-robots. The 'Titles discarded' sentence adds a concrete scope qualifier. However, the schema's 'feed' parameter accepts any 'Public RSS or Atom URL,' creating ambiguity about whether the tool is HN-specific or a generic feed counter.

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. The description names no sibling tool and states no conditions or exclusions, such as preferring this over web-fetch for a quick count. Usage context must be entirely inferred from the single purpose sentence.

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