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

With no annotations, the description itself carries the disclosure burden. It reveals that titles are discarded and that the count is of the current front page, but it does not explain connectivity assumptions, return type, or what happens for empty/failed results.

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 contain no redundant phrasing. The purpose is placed first and the key limitation, title availability, is second. It is efficient without sacrificing readability.

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 tool has 9 optional parameters, no output schema, and no annotations, yet the description only says 'Count current Hacker News front-page stories. Titles discarded.' It does not tell the agent what the returned value looks like, which parameters are relevant, or whether the current front-page count is the whole story. More context is needed for confident 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 each of the 9 parameters has an individual description. The tool description, however, does not explain how any of those multiple parameters relate to counting Hacker News stories, leaving the connection between schema and purpose genuinely 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 states a concrete action and resource: 'Count current Hacker News front-page stories.' It also clarifies that titles are discarded, which helps distinguish the count-only behavior from other fetch-related tools. It does not explicitly compare against the sibling tool set, so it misses the highest differentiation mark.

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?

There is no explicit 'use this tool when...' or 'instead of...' guidance. The phrase 'Titles discarded' implicitly tells the agent not to expect titles, and 'Count' implies the tool is for counts, but concrete exclusions and sibling alternatives are absent.

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