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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds the useful sequencing hint that it should be read before mutation, but says nothing about the shape or size of the returned schema, or whether the described limits are hard constraints.

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?

One compact sentence with the resource front-loaded and the usage rule trailing, no filler. The switch to French inside an otherwise English tool catalog slightly hurts scanability for an English-only agent, but the content itself 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?

With no parameters, no output schema and rich annotations, a short definition is appropriate, and it does enumerate what comes back (schema, defaults, payment methods, limits). A brief note on output structure or on how the returned limits should constrain subsequent calls would make it fully complete.

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 takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly signals that all output is static configuration data rather than request-dependent.

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 a specific resource and output: the schema and default values of customizable Pay forms, plus payment methods and limits. That is enough to separate it from get_payment_page (fetch one page) and list_payment_pages (enumerate them), though it never explicitly frames itself as the discovery step for create_payment_page/update_payment_page.

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?

"Lire avant création/modification" gives an explicit when-to-use rule tied to the create/update siblings, which is exactly the sequencing an agent needs. It stops short of naming those siblings directly or stating when this tool is unnecessary.

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