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

The readOnlyHint annotation covers the read-only nature. The description adds a price ('Prix : 0.050 USDC') and hints at payment requirements, but the schema already details the parameter behavior (absent payment returns instructions). There is no contradiction, but limited behavior is disclosed beyond the annotation.

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 concise and front-loaded with the topic, covering content and price in two short sentences. It is not excessively long, though it could be more structured as tool instructions.

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?

It provides a rich overview of the data content (visitor stats, sustainable labels, market flows, etc.) but does not explicitly state what the output format is, and the payment flow is only partially covered via the schema. The description is adequate but relies on the name and schema to convey full functionality.

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 schema fully describes the single parameter (payment_tx_hash) with its payment-related behavior, so the description need not add more. The description does not mention the parameter at all, which is acceptable given 100% schema coverage.

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 is a descriptive summary rather than a clear statement of function; it lacks an explicit verb indicating that it retrieves tourism data. However, the name and detail (e.g., '870 000 visiteurs 2024') make the subject clear, distinguishing it from sibling tools on other topics.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any conditions, exclusions, or related tools; the topic is implied by the name but not explicitly stated as a recommendation.

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