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

Beyond the read-only and idempotence annotations, it discloses that no account or key is required and that an absent brand produces an error directing the agent to rechercher_offres. It also explains the returned content, including verification date, consulted official page, limited-offer end date, and warnings, which is especially valuable without an output schema.

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 purpose and single-brand scope are front-loaded, followed by selection rules, failure behavior, and access requirements in a logical order. Although dense, the field inventory is useful because there is no output schema, and the remaining sentences all provide actionable information.

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 simple one-parameter read operation, the definition covers scope, expected result content, when to use it, sibling alternatives, missing-brand behavior, and authentication requirements. The absence of an output schema is well compensated by the enumeration of returned fields, and no pagination or other complex invocation behavior appears necessary.

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 already fully documents marque, including common spelling, case-insensitivity, and examples, so the baseline is 3. The description adds operational meaning by requiring one precise brand and routing uncertain names through search, though it adds no further syntax or formatting details.

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 opens with a precise verb, resource, and scope: returning the complete referral-offer record for one brand in the Meilleur Code Parrainage directory. The detailed field inventory and explicit routing to comparer_offres and rechercher_offres clearly distinguish it from its siblings.

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 explicitly says to use the tool when the user names a precise brand and wants to know how to obtain the bonus. It also gives clear alternatives for multiple brands and uncertain names, plus recovery guidance when the brand is absent.

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