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

Annotations already declare the operation as read-only, idempotent, open-world, and non-destructive. The description adds the useful constraint that the minimum supported geographic scope is country level, but it does not disclose return format, pagination, authentication requirements, or other behavioral details.

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 short and front-loads the purpose, then adds two useful constraints. It contains minor filler such as 'by calling this API' and 'when setting a task', but overall it is efficient.

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 zero-parameter lookup endpoint that has an output schema, the description provides the essential purpose and the country-level scope constraint. It could better explain how the returned locations are intended to be used, but nothing critical is missing for invoking the tool.

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 tool has zero input parameters, so the baseline is 4. The description mentions country filtering, but that appears to apply to task setup rather than this tool's own inputs, and there are no parameters for the description to clarify.

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 clearly states the tool returns a list of DataForSEO Trends locations, naming both the verb-like outcome (receive/list) and the specific resource. It implicitly differentiates from sibling location tools by specifying the Trends product, though it does not explicitly contrast with alternatives.

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 some context by noting that locations can be filtered by country when setting a task and that country is the minimum geographic scope. However, it does not say when to use this tool versus sibling location or category tools, nor does it name alternatives.

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