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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavior: data is monthly, and the tool supports two distinct lookup modes. It also discloses the OR constraint between keyword and asin, adding value beyond the 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?

The description is two sentences with a concrete example. Every part earns its place: the purpose, the two modes, the OR instruction, and an illustrative call. No fluff or repetition.

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, four-parameter tool with 100% schema coverage and no output schema, the description provides everything needed to select and invoke it correctly: what it returns, how to switch modes, the required credential pattern, and a full example. No critical gaps remain.

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%, so parameters are already documented. The description adds the crucial relationship 'Pass `keyword` OR `asin`' that the schema does not explicitly convey, and the example demonstrates realistic invocation syntax including marketplace and _apiKey. This goes beyond the baseline schema documentation.

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 verb and resource ('returns monthly search volume and keyword metrics') and immediately distinguishes two modes: by keyword or by ASIN. It clearly identifies this as keyword data, differentiating it from sibling tools like junglescout_product_database and junglescout_sales_estimate.

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 clear context for when to use the tool: look up search volume for a keyword or get top ranking keywords for an ASIN. The instruction 'Pass `keyword` OR `asin`' explicitly states the key usage constraint, though it does not name alternative tools for when this tool is not appropriate.

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