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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral detail beyond the annotations: the exact response envelope `{ count, total, empresas }`, the item fields, the 'até 30 números' contract limit, and the partial-search behavior. This is useful context without contradicting 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 description is compact: one sentence covers purpose and search modes, the second covers response shape and usage constraints, and the final clause routes to related tools. There is no filler, repetition of the title, or unnecessary fluff. Every sentence earns its place.

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 the tool's moderate complexity, the description covers all essential aspects: search criteria, minimum length, required-term behavior, result limits, response shape, and follow-up tooling. The output schema and read-only annotations handle the remaining concerns, so nothing important is missing for an agent to invoke this correctly.

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 100%, so the baseline is 3. The description adds meaning beyond the schema by clarifying that `nome` or `cnpj` is required, that searches are partial, and how `limite` constrains the result list. It also explains the practical intent of the parameters in the context of a large base, which the schema alone does not convey.

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: 'Busca empresas que contratam com o Senado por nome (mín. 3 caracteres) ou CNPJ/CPF (busca parcial).' It clearly identifies the subject (companies contracting with the Senate) and the two search modes. It also distinguishes itself from related sibling tools by pointing to senado_contratos and senado_contratacao_detalhe for follow-up detail.

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 description explicitly states the precondition: 'Exige nome ou cnpj (a base completa é grande)', explaining why at least one search term is necessary. It also names the downstream tools to use with the returned id/contract number, giving concrete guidance on when this tool is the entry point versus when to switch to another tool.

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