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 value beyond that by enumerating what the response covers (trial terms, free tier, Pack pricing TTC, inclusions, supported sites) — effectively substituting for the missing output schema. It does not state whether the pricing is authoritative or could go stale, which keeps it below 5.

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?

Content is front-loaded with the offering and the parenthetical audience qualifier is compact, and the trailing sentence states the use case. The content enumeration is dense but each item earns its place by telling the agent what the answer contains; a slightly tighter phrasing would reach 5.

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 input schema, no output schema and only safety annotations, the description carries the burden of explaining what comes back, and it does so by listing the offering components and pricing-inclusive-of-tax detail. Nothing critical is missing for an agent to call it correctly; only freshness/authority of the pricing data is left 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 to disambiguate; baseline for a no-param tool is 4. The description correctly implies a parameterless, fetch-everything call with no filtering options.

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 concrete subject matter (Fondatoria's offering: 30-day trial without card, free site, Pack complet with TTC prices, what it includes, supported site types) rather than restating the title. An agent can tell this is a static information/FAQ-style tool about pricing, distinct from the 'preparer_*' siblings which imply action. It stops short of explicitly contrasting itself with those siblings by name.

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?

"Pour une question de prix ou de contenu de l'offre" gives an explicit trigger condition for calling it, which is exactly the selection signal an agent needs. It does not name alternatives or state when NOT to use it, so it falls short of a 5.

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