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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true and openWorldHint=true, so safety is covered. The description adds genuinely non-structured behavior: the result is an estimate and not a certainty, and the photo is not stored (a privacy guarantee an agent should be able to relay). It does not mention rate limits, size limits, or error modes, so it stops short of 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?

Content is front-loaded with the core purpose, then outputs, then the caveat, then accepted input forms — a sensible ordering with no filler. The main cost is the full bilingual duplication, which roughly doubles length, though it plausibly serves a bilingual audience.

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 carries the return-value burden and does so well: likely breed with its share, possible mix, and each breed's page. Combined with the estimate caveat, the no-storage note, and accepted input forms, an agent has everything needed to call and interpret this tool.

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%, so the schema already documents espece, langue, photo_url and photo_base64, giving a baseline of 3. The description adds the either/or relationship ('https address or base64') and the mutual exclusivity implied by the schema's 'instead of photo_url', but no extra format or size guidance beyond that.

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+resource: it estimates a dog's or cat's breed from a photo by comparing against Mission Museaux's breed directory and known-breed records. That is unambiguous and actionable, but it never explicitly names or contrasts with the closest sibling, chercher_par_photo, which also takes a photo, leaving the agent to infer the division of labor.

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: the reader infers this is for identifying a breed when the breed is unknown, versus 'races' (browsing the directory) or 'chercher_par_photo' (searching listings by image). There is no explicit when-to-use/when-not-to-use statement and no named alternative, so guidance is thin but derivable from the purpose.

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