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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds the deterministic frequency ordering, which is genuinely useful behavior, but says nothing about pagination semantics, total counts, or what fields a sujet entry carries.

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?

A single front-loaded sentence with the resource first and the sort behavior second; every clause carries information and there is no 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?

For a simple, read-only, two-parameter list tool with annotations covering safety and no output schema, the description is nearly sufficient. The remaining gap is the return shape (does each sujet include a reference count?) and paging behavior, which an agent browsing a potentially large index would want to know.

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 50%: limit is documented inline ('Default 50, max 200') but offset is completely bare. The description adds no parameter guidance at all — no default, no cap, no mention of paging through results — so the undocumented offset is left entirely to guesswork.

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 ('List sujets from the IWAC index') plus the ordering rule ('sorted by frequency, most-referenced first'), so the agent knows exactly what comes back and in what order. It does not, however, distinguish itself from the many sibling list_* tools (list_persons, list_locations, list_periodicals), leaving the agent to infer that 'sujets' is a distinct index facet.

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 frequency sort signals 'browse the most-referenced subjects', which hints at exploratory use. There is no explicit when-to-use statement and no mention of alternatives such as search_index or get_index_entry, which are the obvious siblings for looking up a specific subject.

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