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

Annotations already establish the safe-read profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description is free to add scope detail instead: it discloses that contacts with no Ficiel conversation are included, and that results are paginated with an exact total. That inclusion rule is genuinely non-obvious behavioral context.

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 dense sentences with the scope stated first and pagination last; nothing is padded. Minor awkwardness in the repeated 'quand quand' and the return-shape hint is compressed, but it is appropriately sized.

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 output schema, the description has to carry the return semantics, and it does name the three things an agent needs: who is blacklisted, since when, and the pagination/total fields. It stops short of describing the full record shape, but is complete enough for correct invocation.

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 description coverage is 100% and both parameters (limit, cursor) are documented in the schema, so the baseline is 3. The description reinforces cursor-based paging via next_cursor but adds no syntax or constraint information beyond what the schema already carries.

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 states a concrete resource (les contacts en liste noire) and the returned attribute (depuis quand), so an agent knows this is the read-only view of the organization blacklist. It does not explicitly name the sibling ficiel_blacklist_lead as the mutation counterpart, so differentiation is left implicit.

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?

Usage is implied rather than stated: the tool is the only list-style reader among the blacklist siblings, but the description never says when to reach for it versus ficiel_blacklist_lead or ficiel_ne_plus_proposer. No exclusions or prerequisites are given.

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