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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds useful context about deduplication ('unique') and link direction ('linking to a domain'), but does not disclose behavioral details like limit handling, score semantics, or response format beyond what annotations imply.

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 one concise sentence with no filler. Every word ('unique', 'domains', 'linking', 'domain') contributes to the meaning, making it efficient 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?

For a simple list tool, the description covers the core purpose but leaves gaps: limit and score parameters are unexplained, and there is no output schema or description of the return format. Given the tool's simplicity and good annotations, a score of 3 reflects adequate but incomplete context.

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 0%, so the description must compensate. It implicitly explains the 'domain' parameter as the target domain, but provides no clarification for 'limit' or 'score'. With three parameters, this leaves two ambiguous and fails to fully compensate for the absence of schema descriptions.

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 'Get unique domains linking to a domain' uses a specific verb ('Get') and resource ('unique domains linking to a domain'), clearly distinguishing it from sibling tools like get_backlinks (individual links) by emphasizing uniqueness. It precisely states the tool's 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?

Implied usage is evident: use when you need unique referring domains. However, there is no explicit mention of when not to use it or how it compares to alternatives such as get_backlinks or get_outbound_links. The description lacks direct guidance.

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