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

The description discloses that the tool returns up to 100 items and explains the 'kind' parameter values. With no annotations provided, it carries the full burden but only partially covers behavioral traits (e.g., no mention of authentication, rate limits, or return format). It is adequate but not rich.

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 only two sentences and front-loads the main purpose. Every sentence adds value: the first identifies the resource, the second details customization. No unnecessary 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?

With no output schema and no annotations, the description covers the essential aspects: purpose, parameter variants, and output limit. For a simple listing tool with only two parameters, this is sufficient for an agent to select and invoke it correctly. It could be improved by mentioning the output structure (e.g., story IDs or objects).

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?

Although schema_description_coverage is 0%, the description adds meaning by explaining each 'kind' value (e.g., 'ask' = Ask HN) and stating 'Returns up to 100 items', which clarifies the 'limit' parameter. This goes beyond the schema's enum and numeric constraints, providing useful context for the agent.

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 'Current Hacker News front-page stories' and lists the available kinds (top, best, new, ask, show, job). This effectively communicates that the tool retrieves lists of stories. It distinguishes from siblings like hn_item (single item) and hn_search (search) by focusing on front-page listings.

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 you want top/best/new/ask/show/job stories) but does not explicitly state when not to use it or mention alternatives. It provides enough context for choosing this tool over siblings, but lacks explicit guidance.

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