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

With no annotations, the description carries the full transparency burden, and it does add useful behavior: dataset size, supported filters, per-result URL and Markdown citation link, and the ODbL attribution requirement. However, it advertises filters for 'photo' and 'site officiel' that have no matching parameters in the input schema, which is a transparency and correctness flaw.

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 description is two sentences, front-loads the action and scope, then states the output format and attribution obligation. Every sentence earns its place, and the licensing instruction is actionable rather than generic.

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?

Given seven optional parameters and no output schema, the description covers core purpose, output citation format, and legal reuse, which is adequate for basic invocation. It falls short on declaring how filters in the description map to parameters, and on whether 'photo'/'site officiel' are controllable, pagination, or behavior when no query is 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 description coverage is 100%, so the schema itself documents all seven parameters; the baseline is 3. The description broadly maps query/region/departement to search keys but adds no parameter-specific meaning beyond the schema, and its mention of photo/site filters does not correspond to any exposed parameter.

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 opens with a specific verb and resource: 'Cherche parmi 10 500 châteaux, manoirs et forteresses de France' and lists the search dimensions and filters. This clearly positions it as a search/list tool rather than the sibling get_chateau detail tool, and the domains of list_evenements/list_itineraires are different.

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?

The intended use is implied by the search semantics and by the citation/licence instruction, but no explicit when-to-use versus sibling tools is given. There is no alternative naming or exclusions, though an agent can infer this is the go-to tool for castle searches.

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