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

No annotations are provided, so the description carries the transparency burden. It does disclose that the tool queries CommonCrawl and Open PageRank, implying a read-only external lookup. However, it does not mention response format, interpretation of results, or potential rate/access limitations, leaving some behavioral ambiguity.

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 a single, front-loaded sentence that directly states the tool's function without any filler. Every word carries meaning, making it highly concise and well-structured.

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?

This is a simple one-parameter tool with no output schema. The description covers the main purpose and data sources. It could slightly improve by noting the return shape (e.g., presence boolean and numeric score), but for a low-complexity check tool it is largely complete.

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?

The schema already provides 100% coverage for the single 'domain' parameter, including an example. The description adds no extra parameter-level meaning, so it earns the baseline score for schema-covered parameters. It does not clarify whether the parameter is required, though the schema indicates zero required parameters.

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 states a specific action ('check backlink presence') against a concrete resource ('CommonCrawl index') and a specific metric ('Open PageRank score'). This differentiates it from sibling SEO tools like keyword_research or seo_audit, which focus on other aspects.

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 gives no guidance on when to use this tool versus alternatives. It does not mention exclusions, prerequisites, or when one of the sibling tools would be more appropriate. The context is implicitly 'when you need backlink data,' but no explicit direction is provided.

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