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 genuinely non-obvious behavioural context: the tool operates purely on supplied text and performs no image inspection or product testing, which sets a real expectation about what the analysis can and cannot conclude. It could go further on how inconsistencies are reported, but that is largely covered by the output schema.

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, zero padding, and the core action is front-loaded before the scope limitation. Every clause carries information — the analytical outputs in the first sentence, the input restriction in the second.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile; the description supplies the input-scope caveat that structured fields cannot. What is missing is the routing relationship to 'comparer_pieces', the nearest sibling, which leaves a small gap for an agent choosing between the two.

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 description coverage is 100%; both parameters are documented in the schema, including the example '30 % cachemire, 70 % polyamide ; doublure 100 % viscose' and the rule that an empty appellation means no comparison. The description adds no parameter-level detail beyond that, so the baseline of 3 applies.

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 states a specific verb and resource ('Je lis une composition et je la compare au nom de vente') and enumerates the concrete findings it produces (matière dominante, doublure, totaux incohérents, simili vendu comme du cuir, « effet laine »). An agent immediately understands what the tool returns. It does not, however, distinguish itself from the sibling 'comparer_pieces', which also performs comparison work.

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?

Usage is implied rather than stated: the agent can infer it applies when a label/fiche text exists alongside a sales name. The explicit exclusion — 'Je ne lis que le texte fourni : ni photo, ni test du produit' — is a useful negative boundary. But there is no guidance on when to prefer this over 'comparer_pieces' or 'get_piece_hub', and no prerequisite stated.

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