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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. Beyond that, the description adds genuinely useful behavior: deterministic sampling keyed on the seed (same seed → same cases, reproducible by third parties) and the fact that it is free and needs no key. This is real context an agent cannot get from the annotations.

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 operative content is front-loaded in the first sentence, which is good. However, the description is bloated with editorializing and exhortation ('não aceite sugestão de ninguém', 'Auditoria que exige cadastro não é auditoria') that does not help an agent select or invoke the tool, and the reporting rules belong to the agent's behavior rather than to the tool contract.

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 2-parameter, read-only, no-output-schema tool, the description covers the essentials: it lists the return fields, the data source, the determinism guarantee, and the verification procedure. The one real omission is that the 'n' parameter is never explained, which leaves sample sizing implicit.

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 0%, so the description must carry the param burden. It does well on 'semente' (an arbitrary integer the caller must choose themselves, with determinism implications) but never mentions 'n' (sample size, default 25), which is documented only by the schema's default. Half the parameters are semantically explained, so the description only partially compensates for the coverage gap.

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 ('sorteia casos' – draws cases) and enumerates exactly what each returned case contains (empresa, CD_CVM, exercício, indicador, valor publicado, fórmula, conta CVM), so an agent understands the output without opening a schema. It does not, however, differentiate itself from any of the 23 siblings (veredito, scores, reapresentacoes, etc.), so it falls short of a 5.

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?

Clear on when to use it: to independently re-verify published numbers against the original CVM file, with concrete downstream steps (download dfp_cia_aberta_<EXERCICIO>.zip, filter CD_CVM and ORDEM_EXERC='ÚLTIMO'). It resolves the 'audit this, not our claims' intent well but never names an alternative sibling or an exclusion condition.

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