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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, and 'Lecture seule' simply restates that. What the description adds beyond annotations is genuinely useful: it discloses the exact state machine (brouillon -> soumis -> approuve/rejete -> remplace), that transitions are guarded, and that it executes an illustrative lifecycle with an audit trail and invariant checks.

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?

A single front-loaded sentence that leads with the call condition and then enumerates the states and behaviors. Dense but every clause carries information; no filler.

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 parameters and no output schema, the description must convey what comes back, and it partially does by stating that an example lifecycle with audit trail and invariant verification is produced. An agent knows enough to call it and roughly what to expect; exact return shape remains unstated.

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 for a no-parameter tool is 4.

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 names a specific verb ('decrire') and a specific resource ('environnement de donnees commun (CDE, ISO 19650)') and further specifies that it runs an example lifecycle end-to-end, which makes it unmistakable among the ~90 cao_* siblings. It stops short of naming a sibling it could be confused with, so no explicit differentiation is offered, but the narrow scope does the work implicitly.

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?

It opens with an explicit trigger ('Appelez quand vous devez decrire l'environnement de donnees commun'), giving clear context for invocation. No when-not conditions or named alternatives are provided, which keeps it out of 5 territory.

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