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

Beyond the readOnly/openWorld annotations it discloses pricing ($0.01 per successful call), billing exceptions (bad input free, not-found/no-match not charged), and the x402 USDC-on-Base payment passed in _meta["x402/payment"]. Pagination via next_cursor and the per-hit field set are also described.

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?

A single dense paragraph with the core purpose front-loaded and pricing/payment last, so no wasted lead-in. It is packed tightly enough that the use-case clause and field enumeration compete for attention.

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?

There is no output schema, so describing the per-hit fields and the next_cursor return value is necessary and done. Payment/auth mechanics and cost model are covered, leaving nothing an agent needs before invoking.

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 coverage is 100% and documents q length, the story/comment enum, limit bounds and cursor semantics, so baseline is 3. The description adds only the 'next_cursor gives the next page' linkage between output and the cursor parameter, without format detail beyond the schema.

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?

States a specific verb and resource: 'full-text search of Hacker News stories or comments' via Algolia, which separates it from most social siblings. It does not name the closest sibling (hackernews_thread) or contrast item lookup with search, so differentiation is implied rather than explicit.

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?

It gives a use context ('tech news, launches and developer discussion for market and competitor research') but no when-not guidance and no pointer to hackernews_thread for fetching a specific thread. An agent must infer that this is the discovery tool and the sibling is the detail tool.

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