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 discloses the paid nature, the exact price ($0.10 USDC on Base), that no account or API key is needed, the default ordering, and the response fields. It omits failure behavior (what happens if payment fails), rate limits, and whether payment is charged per call or per result.

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?

Front-loaded with the payment flag, then purpose, ordering, returned fields, cost/access terms, and endpoint. Every clause carries information; nothing is padding.

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?

For a two-optional-parameter read tool with no output schema and no annotations, the definition covers cost, auth, filtering, and returned fields adequately. Only payment-failure and pagination/limit behavior are unaddressed.

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%, so both parameters are already documented in the schema. The description only restates the default sort ('newest first, or sort=top'), adding no syntax or range detail beyond the schema's '1-30 (default 10)' and 'recent (default) or top' — 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?

States a specific action and resource: paid Hacker News stories about 'linux', with the record fields it returns (points, comments, links). That is clearly distinct from the topic siblings such as buy_hn_python or buy_hn_rust and from the general buy_hn.

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 only implied by the topic label – an agent can infer this is the linux-filtered variant of buy_hn, but the description never states 'use this instead of buy_hn when the topic is linux' or when a paid call is warranted over a free alternative. No exclusions or prerequisites beyond the payment note.

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