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

Annotations already establish that this is a read-only, non-destructive, open-world lookup. The description adds useful behavioral context beyond annotations: default US monthly search volume, the 0-100 difficulty scale, credit cost per call for all keywords together, and refund on failed lookup.

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 first sentence states the returned metrics and scope, and the second covers cost and refund behavior. Every sentence earns its place.

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 one-parameter read-only lookup with annotations covering safety and openness, the description supplies the key defaults, limits, returned metrics, and cost behavior. No output schema exists, so no return-format explanation is required.

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 100%, so the keywords parameter and its 1-10 item bounds are already documented in the schema. The description restates the 1 to 10 keyword range but adds no format or semantic detail beyond the schema.

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 gives a specific verb and resource (get keyword data) and lists exactly which metrics are returned: search volume, keyword difficulty, CPC, and search intent. It is clear what the tool does, but it does not explicitly distinguish itself from sibling tools such as get_keyword_ideas or get_search_console_keywords.

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 states the input range and cost but gives no explicit guidance on when to use this tool versus alternatives like get_keyword_ideas. Usage is only implied by the metric list, with no when-not conditions or sibling routing.

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