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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently explains the domain-level-only limitation, ranking logic, free vs Pro row/domain limits, and output scope. It does not mention failure modes or rate limits, but the disclosed behavior is sufficient for selection and calling.

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 front-loaded: the core operation appears first, followed by the use-case metaphor, then constraints. The illustrative 'must-have publications' phrase earns its place by clarifying intent, and no sentence is redundant or 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?

For a single-parameter tool with no output schema, the description is complete enough: it explains what the tool returns, how results are ordered, what data is excluded, and how tier limits affect both input and output. Nothing critical is missing for an agent to decide whether to call it and interpret the result.

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 100% for the single 'domains' parameter, including the 2-4 range, example format, and free-tier first-two behavior. The description reinforces that the parameter is a list of root domains but adds no new parameter-level semantics beyond what the schema already provides, so the baseline score of 3 applies.

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 states a specific operation with a clear object: given 2-4 domains, return the domains linking to more than one of them, ranked by overlap then authority. It also differentiates from the sibling top_linkers_for_domain by focusing on multi-domain intersection rather than a single domain.

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 communicates the intended use case clearly: 'who links my whole niche?' and mentions tier limits (free/Pro), which implies when the tool is appropriate. It does not explicitly name a sibling alternative or state when not to use it, so it stops short of a 5.

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