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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered; the description adds the concrete return shape ({id, title, text, url, metadata}) and clarifies that 'text' holds the entire record as JSON. That is real behavioral context beyond the annotations, though it says nothing about what happens when an id does not exist or is malformed.

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 core action and its precondition front-loaded, followed by return shape and the type list. Every clause carries information an agent needs; nothing is redundant padding.

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 correctly compensates by naming the returned fields and explaining that the full record lives in 'text'. For a single-parameter read tool this is nearly complete, with only error/not-found behavior left unaddressed.

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 100% and the schema already documents the id format 'type:numéro' with an example, so the description adds little about the parameter itself. The type enumeration does help the agent construct or validate a valid id prefix, which is modest added value over the schema, but it is not framed as a constraint on the id 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?

States a specific verb and scope ('Lit en entier') plus the resource ('un élément trouvé par search'), and enumerates the 15 supported record types, which tells the agent exactly what universe of entities it can retrieve. It implicitly contrasts with search (search finds, fetch reads in full) but never says so explicitly, so it stops short of a perfect sibling differentiation.

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 'trouvé par search' establishes the precondition clearly: the id must come from a prior search call, so the agent knows this is a second-step detail-retrieval tool. There are no explicit exclusions or named alternatives for cases where a summary would suffice, so it is clear context without 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.