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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the payload content (field spec shape, calculation method, official sources), which tells the agent what kind of information it will receive and why it matters before computing.

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 verb and the returned content, closing with the routing instruction. No filler, though the enumerated content list is dense and 'cas fréquents' is slightly vague, keeping it just short of ideal.

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?

No output schema exists, so the description carries the burden of describing returns, and it does so by enumerating the field spec, calculation method, official sources, and use cases. With one well-documented parameter and annotations covering safety, only finer details of return format are 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?

There is a single parameter and schema description coverage is 100%, so the schema fully documents 'slug' including its source (list_calculators). The description adds no parameter-level detail, so the baseline of 3 for schema-driven params is appropriate.

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 opens with a specific verb and resource ('Décrit un calculateur Vitef') and then enumerates exactly what is returned: expected fields (key, label, type, options, default), calculation method, official sources, and common cases. It also differentiates itself from the sibling compute_calculator by positioning itself as the inspection step that precedes computation.

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 final clause 'À appeler avant compute_calculator' gives an explicit when-to-use and names the alternative tool, which is strong routing guidance. It stops short of an exclusion (e.g. what to do if you already know the field schema), so it is clear context rather than a full when/when-not rule set.

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