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

Annotations already cover read-only/idempotent/open-world safety, but the description adds genuinely useful context beyond them: the photo is not retained, the comparison uses the association's own vision model, and results include a likeness score plus an estimated breed. It does not mention latency, result limits, or behavior when nothing matches.

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?

Core capability is front-loaded and every sentence carries information, but the full French/English duplication roughly doubles the text and the website mention is tangential to invoking the tool.

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 usefully spells out what comes back (ranked listings with percentages and estimated breed) and the privacy behavior. The main gap is that no parameter is marked required, yet a photo is essential; the description never says photo_url or photo_base64 must be supplied.

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 coverage is 89%, so the schema already documents nearly every parameter, including the base64-instead-of-URL rule. The description only restates that an https URL or base64 image is accepted and that cats/dogs are supported, adding little beyond the schema; baseline 3 is appropriate.

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 ('Compare une photo d'animal ... aux photos des annonces') and names the outputs (similarity percentage, estimated breed). The photo-matching capability is inherently distinct from the text-oriented siblings (chercher_annonces, chercher_adoptions) and from reconnaitre_race, so an agent can tell what this tool is for without opening the 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?

Usage is only implied: it is clearly the tool for finding a lost/found pet from a picture, and it notes the web page for phone-based uploads, but it never states when to prefer it over reconnaitre_race (which also estimates breed) or the text search siblings, nor any prerequisite conditions.

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