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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds real value on top by disclosing the returned fields (prix barré, pourcentage de réduction, date de fin if applicable), which is the only source of return-value information since no output schema exists. It does not mention ordering, empty-result behavior, or what 'si applicable' means for missing end dates.

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 filler, with the purpose stated first and the return shape second. Every clause earns its place.

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?

For a low-complexity read-only list tool with one optional parameter and no output schema, the description covers purpose and return fields well. Minor gaps remain around result ordering, pagination/truncation when limit is hit, and behavior when no promotions exist.

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% and the single 'limit' parameter (default 10, max 50) is fully documented in the schema. The description adds nothing about pagination or whether limit caps the promo scan, so baseline 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?

Specific verb ('Lister') + resource ('produits actuellement en promotion') + scope ('actuellement', implying a live/current filter). This is clearly distinguishable from get_best_sellers, get_new_arrivals, and search_products by the promotion criterion, though the description never names those siblings explicitly.

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 only implied by the word 'actuellement' — an agent can infer this is the tool for discounted items, but there is no explicit when-to-use/when-not statement and no routing to search_products or get_product for non-promo lookups. Adequate but leaves the alternative selection to inference.

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