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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds the notable fact that the authority score is Pylon-computed on a 0-100 scale, which clarifies the returned metric's origin. It still omits result count, ordering, and whether the list is paginated, which matters for a 'top N' style endpoint.

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 with no filler; the resource is stated before the qualifier. Minor jargon ('Pylon-computed') is the only cost.

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 simple read-only list tool with a fully documented single parameter, the description is adequate but leaves the return shape ambiguous — 'Top' implies a limit and ranking that are never quantified, and no output schema exists to resolve it.

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?

Only one parameter, and schema description coverage is 100% ('UUID of the site'), so the schema carries the semantics fully. The description adds nothing about the parameter, which is acceptable at this coverage level.

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?

Names a specific resource (referring domains) and scope (top, for a site), plus the authority metric returned. It is clear what the tool fetches, though it does not distinguish itself from any sibling because no other backlink-domain tool exists in the set.

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?

There is no when-to-use guidance, no prerequisites (e.g., that a prior scan or crawl must exist), and no alternatives named. The agent must infer usage entirely from the name and the required site_id.

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