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

Annotations only declare readOnlyHint and openWorldHint, but the description adds a lot of substantive behavior: per-country coverage windows (DZ 1962, MA 1912, TN 1956), the fact that Tunisia's pdf_url is always null because the official site exposes no direct PDF links, and that Moroccan supplements (bis/ter) are listed alongside their parent issue with a suffix. These are non-obvious data quirks that materially affect interpretation of results.

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?

Front-loaded with the default country (Algeria) and then the two variants, with the routing instruction last. It is long — three dense sentences with repeated 'For each issue...' structure — but since there is no output schema, most of that detail is load-bearing rather than filler.

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-shape burden and does so thoroughly: it enumerates returned fields per country (issue number, edition existence, PDF links, publication date, summary availability), notes the null-pdf_url case and the error behavior. Nothing needed to call or interpret this tool 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 year bounds, the country enum/codes and the lang enum. The description reinforces the country mapping and year ranges but adds little syntax or format detail beyond the schema's own parameter descriptions, 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+resource (list the Journal Officiel issues for one year) and then precisely differentiates scope per country, including what each row contains. It explicitly distinguishes itself from siblings get_jo_issue (contents) and list_jo_years (years covered), so an agent can route without opening any 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?

Gives explicit when-to-use guidance: 'Use it to find the number of an issue, then get_jo_issue to see what the issue contains', and points to list_jo_years for picking a valid year and list_countries for valid countries. It also states the failure condition (error when no issue is indexed for the year), which is a clear exclusion/edge case.

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