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

With no annotations at all, the description carries full burden; 'lire' implies read-only, and it does disclose the range of retrieval modes (fiche/plan/article/arrêt), which is genuinely useful. It is silent on truncation behavior (max_caracteres), pagination, and permission/auth requirements, leaving the mutation-free but incomplete picture thin.

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 is front-loaded in the first clause, and the two following fragments carry only format examples with no filler. The telegraphic style is dense but every element 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?

An output schema exists, so return values need not be explained. However, the description never clarifies how the output mode is chosen (omitting 'article' for a fiche/plan vs. supplying it for article text) or what max_caracteres truncation does, which is a real gap for an agent trying to call it correctly the first time.

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 coverage is 0%, yet the description compensates heavily for 'reference' (CELEX, alias, citation forms, case number, ECLI) and 'article' ('17', 'premier', 'Annexe III') with concrete examples. Only 'max_caracteres' is left unaddressed, and its name plus the 20000 default make it largely self-explanatory.

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 gives a specific verb plus resource ('lire' + 'Droit de l'UE') and enumerates the retrievable outputs (fiche, plan, article, arrêt text), which is far beyond restating the name. It doesn't contrast itself with nearby siblings like rechercher_droit_ue or lire_texte, but the UE scope disambiguates well enough on its own.

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 acceptable reference and article input formats are spelled out, which implies when the tool applies, but there is no explicit guidance on when to choose it over rechercher_droit_ue or lire_article, and no mention of a lookup-first workflow. Usage is therefore inferable rather than stated.

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