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

With no annotations, the description carries the full burden and does well: it enumerates return contents (stories, points, comment counts, thread links, aggregate totals, top domains, first/last discussion time) and even discloses cost ($0.004). It stops short of stating rate limits, auth needs, or failure modes, keeping it from a 5.

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 front-loaded sentence leads with the resource and value, then enumerates outputs and appends the price. It is efficient with little waste, though the aggregate enumeration is dense.

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 the description appropriately describes the return payload in detail and adds pricing. For a read-only search tool with full schema coverage, this is nearly complete; only rate-limit or permission behavior is left unstated.

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 query, sort, and limit are already fully documented in the schema. The description adds no parameter syntax or format meaning beyond that, so the baseline of 3 applies.

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 specific resource (Hacker News stories/discussions) and what is retrieved (matching stories with points, comment counts, thread links, plus aggregates). It clearly distinguishes itself from generic siblings like search_web or search_news by scoping to Hacker News, though it never names those alternatives.

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?

Usage is implied by the topic ('What Hacker News said about a topic'), but there is no explicit when-to-use guidance, no when-not-to-use, and no routing to alternatives such as search_news for general news or search_web for the broader web.

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