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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the cost model ($0.002 in USDC per successful call via x402 on Base, Solana or Arc) and that failed calls are not charged, plus result-bound behavior (top 20 ranked, newest 60 for search). These are agent-relevant economics and scope facts that annotations cannot supply.

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?

Roughly four dense sentences that are front-loaded with the modes before the field list, limits and pricing. Every sentence carries information, though the field enumeration and pricing sentence could be tightened slightly.

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 a 4-parameter, no-required, all-optional schema, an existing output schema, and annotations covering safety and openness, the description fills the remaining gaps: what each mode returns, the caps on results, and the payment mechanics. Nothing needed to invoke it correctly is missing.

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 q, mode, topic and limit is already documented, and the baseline is 3. The description adds a concrete topic slug example and clarifies that mode 'today' means a ranked top-20 snapshot, but it says nothing about the limit parameter's 1-20 range 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?

The description names a specific resource (Product Hunt launches) and enumerates the three distinct retrieval modes (today's top launches, newest in a topic, text search), so an agent can immediately tell what it returns and in what shape. The field list (name, tagline, votes, comments, launch time, links, topics) reinforces the resource identity and distinguishes it from generic search siblings.

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 explains the selection logic between modes (topic example 'artificial-intelligence', search intent) and states concrete constraints: today = top 20 by ranking anchored to the UTC date, search = newest 60 only. It stops short of explicit when-not-to-use guidance or naming an alternative sibling (e.g. hn_search for Hacker News), so it is clear context without exclusions.

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