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

With no annotations provided, the description carries the full burden and excels. It discloses that 'Nothing is fetched and nothing is spent,' that stored lists are a 'SAMPLE' with implications for absence interpretation, and that positions reflect 'ranking footprint, never traffic.' It also mandates repeating a disclaimer sentence wherever results are shown—an important behavioral requirement.

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 fairly long but each sentence contributes critical caveats or definitions. The structure front-loads the core definition, then layers constraints and disclaimers. It could be slightly tightened (e.g., 'nothing fetched/spent' could be one clause), but overall it is dense and purposeful.

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?

Given the tool's simplicity (one parameter, no output schema), the description is exceptionally complete. It explains the computation logic, data source, limitations, and required response handling, covering all areas an agent needs to use the tool correctly and interpret its results.

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 sole parameter 'domain' is fully described in the schema with an example. The description adds context that the domain must be 'cataloged' and 'claimed,' but does not elaborate on format or validation beyond that. Since schema coverage is 100%, the description's addition is marginal but non-zero, meriting the baseline 3.

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 opens with a specific verb and resource ('Get the keyword gap for a cataloged domain') and defines the gap precisely with two concrete cases ('absent' and 'behind' by 20 places). This distinguishes it clearly from sibling tools like get_competitive_snapshot or get_engine_visibility, which address different analytical angles.

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 explicit applicability conditions: 'Claimed domains only' and 'computed from captures already on disk.' It also clarifies that no fetching or spending occurs, which signals a low-cost read operation. However, it does not explicitly mention alternatives or contrast against sibling tools, so it stops short of full guidance.

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