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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context on top: the exact-vs-approximate resolution semantic, the single-argument constraint, and the shape of the result (productId, sku, nom, url). It does not cover failure modes (e.g. unknown SKU), which keeps it from a 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?

Two dense sentences, front-loaded with the transformation and result shape, followed by the routing rule and the invocation constraint. Every clause carries information; no filler.

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?

A read-only resolver with no output schema; the description compensates by naming the returned fields, and annotations cover safety while the schema fully documents parameters. Nothing an agent needs to select or invoke it correctly is missing.

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?

With 100% schema coverage the baseline is 3, and each parameter is already documented in the schema. The description adds meaning beyond it by stating mutual exclusivity ('exactly one argument') and the provenance of each identifier (sku from-LD, url of the page, productId from search_products), which the schema does not express.

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 ('Convertit une identité EXACTE en identité complète') and enumerates both the accepted inputs (sku, url, productId) and the returned fields. It explicitly names and contrasts with the sibling search_products, so an agent can distinguish the two without opening either 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?

Gives an explicit preference rule: 'À PRÉFÉRER à search_products dès que vous tenez l'un des trois', plus the reason (recherche approximative vs. exacte). It also states the invocation constraint ('Fournissez exactement un argument'), leaving nothing to inference.

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