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

readOnlyHint=true already declares the safety profile, so the description's job is to add context — which it does by disclosing the payload shape (each promoter with its program and available-lot counts) and the implicit scope limit (only M2 partner promoters in the catalog). No auth, rate-limit, or ordering/pagination behavior is mentioned.

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, no filler, with the resource and return content front-loaded and the routing hint second. Every clause earns its place.

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 zero-param read tool with no output schema, the description covers what is listed, what is returned, and when to call it. Minor gaps remain: whether the full catalog is returned at once and in what order, which matters since there is no output schema to fall back on.

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. It correctly avoids inventing filtering options the schema does not expose.

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?

States a specific verb and resource ("Liste les promoteurs partenaires de M2 présents dans le catalogue") and adds what each entry carries (program count, available lot count). It also names the sibling it feeds into (search_lots), so the agent can place it in the workflow without opening another schema.

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 second sentence gives a concrete trigger: use it to identify a promoter the buyer mentions, before filtering search_lots. That is a clear when-to-use plus an alternative-tool relationship. It stops short of stating exclusions (e.g. when to go straight to search_lots or get_program instead).

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