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

With no annotations provided, the description must carry the behavioral burden. It discloses that the HOST should cluster raw tool mentions into canonical names, which is a key behavioral trait (the tool doesn't return raw mentions but canonicalized ones). It also implies it is a read-only analysis tool, though it doesn't explicitly state that. It doesn't mention any side effects or limitations, but the given trait is important and non-obvious.

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 concise, with three sentences covering purpose, pairing, and a behavioral note. It's front-loaded with the main purpose, and each sentence adds value. No redundant content. However, it could have integrated the pairing hint more smoothly, but overall it's well-structured.

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 an output schema, so return value details are covered there. But the description lacks explicit guidance on parameter usage (e.g., how `since`/`until` work, what `topic` should be more precisely, how `limit` behaves). It also doesn't mention any rate limits or required permissions. An agent might not know whether to fill in the date parameters or what to do with the canonical clustering behavior. It's sufficient for a basic call but leaves some ambiguity.

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 50%, with `topic` and `limit` having descriptions, while `since` and `until` lack any schema description. The description doesn't compensate for the missing semantics of `since` and `until`—it doesn't explain that they are date filters or what format they expect. For a topic-based tool, the parameter meanings are relatively clear from context, but the gap means the score stays at baseline 3.

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 that this tool returns tools recommended by the HN community for a given topic, and it pairs with hn_topic_painpoints. It is distinct from siblings like hn_topic_painpoints and hn_ideas, though it doesn't explicitly name all alternatives. A minor gap is that it doesn't specify the exact output format, but the core purpose is clear.

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 tells the agent to pair it with hn_topic_painpoints for a dual pain+recommendation view, giving clear context on when to use it. It doesn't explicitly say when NOT to use it or list other alternatives, but the pairing hint is valuable. The sibling set includes hn_topic_painpoints, which is a strong complement, and the description effectively guides the agent toward a combined workflow.

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