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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real context beyond them: the call returns a link, the assistant then proposes style/colors/texts, and the site builds live in front of the client. That end-to-end workflow is genuinely useful and consistent with readOnlyHint=true since nothing is persisted here.

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 sentences, front-loaded with the action and the return value. The closing clause « le site se construit sous les yeux du client » is slightly promotional but still conveys that the assistant takes over after the call, so it earns most of its space.

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 explaining what is returned (a link) and what happens next. For a two-parameter preparation tool with full annotation coverage, the remaining gap is minor — no mention of failure cases or what happens if the description is rejected by the length bounds.

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%, so both parameters are already documented, including the notable « Ignoré » semantics of the formule enum. The description only reinforces that the activity description arrives pre-written; it adds nothing about the formule quirk or the 20–2000 character bounds, so the schema is doing the heavy lifting.

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 resource (prépare la création d'un site vitrine) plus the concrete return value (le lien vers l'assistant de création). The qualifier « pour une entreprise qui n'en a pas encore » implicitly distinguishes it from the sibling preparer_refonte, so an agent can route between the two without opening the 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 condition for use is stated clearly: a business that does not yet have a site. That doubles as an exclusion (an existing site points to refonte) and the post-call flow is described. However, no sibling is named explicitly, so the routing is inferred rather than spelled out.

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