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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavioral context beyond them: unknown dates are made explicit rather than omitted, and the data is explicitly uncertified ("à confirmer, sans certification de compétence"), which tells the agent how to caveat the values it reads.

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?

Three short sentences, front-loaded with the verb and field list, followed by two caveats that each carry real information. The telegraphic fragments ("Dates inconnues explicites") are terse to the point of ambiguity, which slightly undercuts readability, but nothing is redundant.

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?

An output schema exists, so return structure need not be restated, and annotations cover the safety profile; the description fills the remaining gaps (where the key comes from, data reliability caveats, field coverage). Missing only failure behavior for an invalid or unknown slug, which would matter for a lookup-by-key tool.

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 0%, so the schema only supplies a pattern and length constraint for `slug`. The description compensates by explaining the parameter's provenance and contract — it is a lookup key obtained from search_cabinets — which is the single most important thing an agent needs to satisfy the required parameter.

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?

Names a specific verb and resource ("Lire une fiche par slug") and enumerates exactly what the record contains: identity, address, legal information, activities, sources, canonical URL. It also distinguishes itself from the sibling tool by stating the slug comes from search_cabinets, so an agent can separate this read-by-key tool from the search tool without opening either 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 phrase "slug obtenu dans search_cabinets" establishes the prerequisite step and effectively routes the agent to search first, then fetch by slug. It stops short of explicit exclusions (e.g., what to do when a slug is stale or the record is absent), so it is clear context rather than full when/when-not guidance.

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