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 behavioral context: it discloses the per-country return contents (names, capital, region, population, CNRC/CASNOS office details vs. ISO/INS codes and chief town) and states that an unknown code yields an error, which the annotations do not convey.

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 primary case (Algeria) is front-loaded in the first sentence and the language-specific variants follow in order. It is somewhat long and repeats the 'names in the three languages and chief town' phrasing across the TN and MA sentences, though the per-country field lists do carry distinct information since there is no output schema.

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 takes on the burden of describing return values and does so per country variant; all three parameters are documented and error behavior (unknown code, country_not_available) is covered. Nothing an agent needs to call 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%, so the schema already documents code, lang and country in full detail, including the two-digit pattern and the TN-11/MA-06 accepted forms. The description restates the same code semantics per country without adding format or constraint information 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 (get) and resource (a single Algerian wilaya / Tunisian governorate / Moroccan region) identified by a two-digit code, and enumerates what is returned for each country variant. It also names the sibling tool (list_wilayas) used to discover codes, so an agent can distinguish it from the list/search siblings.

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?

Gives clear context: use it once you have a code, and use list_wilayas to find codes; it also explains that an unknown code returns an error. What is missing is explicit when-not guidance (e.g. how it differs from list_countries or when to prefer bulk listing), but the retrieval context is unambiguous.

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