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

The annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds useful behavioral context beyond the annotations: pricing per call, a free daily quota, the official Algolia source, and the exact fields returned. There is no contradiction with the annotations.

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?

Three dense sentences with no filler. The search action, filters, and return fields are front-loaded, while the pricing and source details come at the end. Every sentence adds value.

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 description is quite complete for a tool with no output schema: it lists returned fields, pricing, rate limits, source, and key filtering options. Minor gaps remain around the limit parameter and full type enum, but an agent can invoke the tool confidently with this description plus the schema.

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?

With 0% schema coverage, the description must compensate, and it does partially: it maps query, sort, days, min_points, and roughly type. However, it omits the limit parameter and the show_hn/ask_hn type variants, so not every parameter is semantically clarified.

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 the exact resource ('Hacker News stories and comments') and the action ('search by keyword'), and it specifies sorting and filtering capabilities. This is specific enough to distinguish it from sibling search tools like arxiv_search or book_search, even though it doesn't explicitly name them.

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 clear use case — finding what developers are saying on Hacker News — and identifies the underlying Algolia service. However, it does not explicitly state when not to use it or which alternative tool to choose, though no sibling appears to cover HN content.

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