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

The description discloses several important behaviors beyond the annotation hints: cost tiers by size, free known-empty lookups, the quote-and-confirm flow for size 1000, and the subtle caching exception for dofollow-only empty results. This is exactly the kind of operational context an agent needs.

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 compact sentences front-load the output fields, then cover cost and confirmation behavior, then state the return shape. Every sentence earns its place and there is no repetition of schema content.

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 read-only listing tool with no output schema, the description is complete: it explains what results contain, how cost works, when confirmation is required, and what the response returns (`limit` and `total_count`). No critical operational detail is missing.

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 the baseline is 3. The description adds meaningful context beyond the schema by clarifying strongest-first ordering, the default and purpose of `limit`, and the dofollow-only empty-result caching exception. It does not need to repeat schema-parameter details.

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 opens with 'Individual backlinks pointing at a target, strongest first' and enumerates the returned fields (source URL/domain, anchor text, dofollow, link type, rank, spam score, seen dates, flags). This makes the tool's precise role clear and differentiates it from sibling backlinks_* tools that focus on anchors, domains, or overview metrics.

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 clearly implies when to use the tool, especially for link-level detail, but it never names an alternative or states when not to use it. Sibling tools like backlinks_anchors and backlinks_referring_domains exist, yet no routing guidance is provided beyond the phrase 'Individual backlinks.'

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