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

Annotations already declare read-only and non-destructive behavior, so the description's additional billing behavior is valuable context. It adds cost details, a free-when-empty condition, and repeat-free behavior, and the return shape, none of which are visible in 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?

The description is compact and information-dense, with the metric list front-loaded, followed by cost and return details. The long list of metrics is slightly unwieldy, but every sentence earns its place and there is no filler.

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?

With no output schema, the description adequately summarizes the return content as the profile summary plus monthly history. It covers the main metrics, pricing, and free-call behavior; the quote-confirmation parameter is already documented in the schema, so nothing needed for invoking the tool 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 does not add any parameter-specific meaning beyond what the schema already provides for target and confirm_quote_id.

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 clearly identifies the resource as 'a target's backlink profile' and enumerates the specific aggregate metrics returned (total backlinks, referring domains/pages/IPs, domain rank, spam score, etc.). This distinguishes it from sibling tools like backlinks_list, backlinks_anchors, and backlinks_referring_domains by its aggregate, overview-oriented scope.

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 overview nature of the output implies when to use it, but the description never explicitly states when to prefer this over backlinks_list, backlinks_pages, or backlinks_referring_domains. There is no 'use this for X, use that for Y' guidance; usage is only implied by the metric summary.

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