Referring Domains

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

No annotations are provided, so the description carries the full behavioral burden. It never states that this is a read-only operation, says nothing about API-unit cost (only the schema's limit field mentions units), pagination, or rate limits, and gives no indication of how the authority ordering is produced.

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?

One front-loaded sentence with no filler or repetition; the resource and the ordering are stated first and the value proposition second. It is efficient, though it is arguably too short given the gaps it leaves.

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 3-parameter tool with no annotations and no output schema, the description omits the two most decision-relevant details: what target values are acceptable and how target_type alters results. The agent has enough to attempt a call but not enough to call it confidently or to disambiguate from siblings.

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 coverage is only 33%: target and target_type are undocumented in the schema, and the description adds nothing about accepted target formats or what root_domain vs domain vs url changes. With low coverage the description should compensate, and it does not.

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?

States a specific resource (referring domains) and its scoping to a target, plus the ordering dimension (authority), so the agent knows exactly what comes back. It does not distinguish itself from close siblings like semrush_backlinks or semrush_backlinks_overview, so the agent must infer the difference.

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?

"Audit link quality and find link-building prospects" implies the use case, which is more than nothing. However, no alternative tool is named and no condition is given for choosing this over semrush_backlinks or semrush_backlinks_overview, leaving routing to inference.

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