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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds real business context not in annotations: the price is one-time with no subscription, and the response covers what's included plus purchase steps. It doesn't say whether pricing is guaranteed/current or what happens for unsupported countries.

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?

Two sentences, zero filler. The what-is-returned content leads and the parameter instruction follows, which is the right ordering for an agent deciding whether to call it.

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 one-parameter read-only lookup with a fully documented schema, the description covers purpose, price model, and the country-to-price relationship. It's slightly thin on what the returned offer actually looks like (fields, whether a purchase link is included), but that's a minor gap given the simple surface.

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 already documents the ISO 3166 alpha-2 format with examples, so the baseline is 3. The description adds the meaningful detail that country drives a localized price — explaining why the parameter exists, not just its format.

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 the specific resource (Featured listing pricing on EveryAI) and enumerates its payload: cost, inclusions, and purchase process. That's a clear verb+resource picture. It doesn't explicitly name a sibling like prepare_submission to distinguish itself, keeping it at 4.

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?

'How a founder buys it' and 'Pass the founder's country for their price' imply the usage scenario (a founder evaluating/acquiring a Featured listing), but there is no explicit when-to-use versus when-to-use-something-else guidance. With a sibling like prepare_submission clearly adjacent, an explicit boundary would have earned a 4 or 5.

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