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

Annotations declare readOnlyHint=false with destructiveHint=false, and the description usefully discloses the cost of the call ('1 credit') plus the fact that the response enumerates what is not included. It stops short of explaining that the call is billable/non-read-only in the annotation's terms, or describing latency or failure modes.

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?

Four sentences, front-loaded with the usage condition and then the return shape, with no filler. The 'ask the user if they are missing' clause is the only slightly procedural addition, but it earns its place for a tool with required inputs.

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 compensates well by enumerating the returned cost breakdown line by line. It leaves the tuning parameter (ajustements) and the lot/campaign parameters semantically thin, but an agent has enough to select and invoke the tool correctly.

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 71%, so the schema already documents most parameters (including examples for matiere and the plan_id origin). The description only reinforces that material and quantity are required and should be asked for if absent; it says nothing about ajustements, lot_de_fabrication, nb_campagnes, or epaisseur_mm beyond what the schema carries.

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 gives a specific verb and resource (estimate what a manufactured part should cost) plus a concrete output shape (material, operations, setups, overheads, margin). It never names a sibling tool, and the phrase 'quote check' overlaps with verifier_devis, so the differentiation is implicit rather than explicit.

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 states the triggering situations (should-cost, target price, quote check), the precondition (a plan_id is available), and an explicit exclusion ('Do not use for general price questions without a drawing'). It also tells the agent what to do when inputs are missing: ask the user for material and quantity.

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