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

Annotations already cover readOnly/idempotent/non-destructive/openWorld, so the description usefully adds beyond them: it discloses the bounded result semantics, that example data does not verify price/inventory/orders/commission, that answer prose is not positive evidence, and that on failure the agent should inspect isError and structuredContent.recovery. These are substantive behavioral constraints not encoded in 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 prose is dense and repetitive, with the 'questions may ask about unsupported claims / answers are not positive feature evidence' caveat appearing in both the description and the query param. Defensive disclaimers dominate and bury the actionable core; sentences are long and front-loading is weak.

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 7-parameter, no-output-schema, no-annotation-gaps tool, the description covers safety, evidence semantics, and failure recovery adequately. What it lacks is any sense of what the response contains or how paginated/bounded results are shaped, which an agent needs given there is no output schema.

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?

With 71% schema coverage the schema already carries much of the load, and the description echoes the key filters (literal keywords, guide example country, native currency, merchant, unit) without adding format detail. limit/offset are never mentioned and the added param prose largely restates the schema's own descriptions, so it adds only marginal value over structured fields.

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?

It does identify a verb and resource (find/discover KR/US buying questions and guide documentation by literal keywords), and implicitly contrasts with find_purchase_candidates by insisting it is not 'exact candidate membership.' But the opening sentence crams 'dated comparison evidence and exact product routes' in, which muddies whether the tool returns questions, evidence, or products. An agent knows roughly what it does but the purpose is diluted by defensive caveats.

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?

It gives implied when-nots ('not general translation,' 'examples do not replace actual buyer selections,' 'not exact candidate membership, current stock or compatibility'), which helps exclude misuse. However, it never names a sibling as the alternative to use instead when the agent wants actual products, leaving routing to inference.

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