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 only that the detail is 'public' and that it includes 'ce que l'on peut faire depuis sa page' (available actions), which is mild extra context; it says nothing about auth, rate limits, or error behavior for a bad/expired id.

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?

The core purpose and content list are front-loaded in one efficient sentence. The trailing English one-liner largely duplicates the French rather than adding information, which costs a little space but does not obscure the main content.

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 read-only detail tool with full annotation coverage, a complete input schema, and no output schema, the description helpfully previews what the response contains (fields, observation count, available actions). Nothing critical to invoking 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?

Schema description coverage is 100% for both parameters, so 'annonce' (id or https address) and 'langue' (fr/en enum with default) are already fully documented. The description adds no syntax or format detail beyond the schema, so the 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?

States a specific verb and resource ('Le détail public d'une annonce') and enumerates the fields surfaced (description, distinctive marks, location, dates, photos, observation count, breed), so the agent knows this returns a single listing's full record. It is distinguishable from the sibling 'chercher_annonces' only implicitly, via the singular 'une annonce' and 'détail', with no explicit contrast drawn.

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 by 'détail ... d'une annonce' and by the singular required 'annonce' identifier, but there is no statement of when to prefer this over chercher_annonces/chercher_par_photo, nor any prerequisite or exclusion. Adequate but leaves routing to inference.

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