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

Annotations already convey readOnly=true, openWorldHint=true, and non-destructive. The description adds valuable behavior beyond annotations: the one-credit cost, the free-when-no-rankings clause, and what the returned summaries cover. No contradiction with annotations.

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?

Three crisp sentences: scope, cost condition, and output summary. No filler or repetition of the schema. The most decision-relevant information (what it returns, cost) is front-loaded.

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 read-only overview query with no output schema, the description adequately states what the tool returns (organic and paid summaries) and the cost condition. It could mention output granularity or pagination, but those are minor given the annotations and the narrow scope.

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%, and each parameter already has a descriptive comment (e.g., 'us', 'gb', paths stripped, list_countries call). The description does not need to repeat parameter details. The mention of cost and free tier relates to billing, not parameters, so baseline 3 is appropriate.

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 names a specific resource (a domain's organic and paid search footprint) and enumerates the exact metrics returned: ranking keywords, estimated traffic, traffic value, position distribution, and movement. This distinguishes it from tools like backlinks_overview or ai_check without needing to open the schema.

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?

No guidance is given about when to choose this tool over its siblings (e.g., ai_overview, backlinks_overview). The cost note and free-when-no-rankings condition are billing facts, not usage direction. An agent seeing sibling names gets no decision support.

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