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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable context beyond that: 'sem credenciais', 'pague por consulta com crédito pré-pago', 'ACESSO PÚBLICO', and LGPD obligations. It does not contradict annotations and provides meaningful behavioral nuance.

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 three concise, purposeful sentences. It front-loads the main purpose, then adds operational and legal context without redundancy. 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?

Although the description provides strong legal/cost context, it lacks critical operational details: how to format CPF/CNPJ, the contradictory requirement of both vs either field, what 'completo' does, and what the return value looks like. With no output schema or parameter descriptions, the agent cannot reliably invoke the tool.

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 0%, so the description must compensate. It mentions 'a partir do CPF ou CNPJ' giving some meaning to Cpf/Cnpj, but contradicts the schema which requires both fields. The optional 'completo' parameter is not explained at all, leaving its purpose unclear.

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 clearly states the tool's purpose: 'Verifica se uma pessoa ou empresa consta no Cadastro Nacional de Empresas Punidas (CNEP) a partir do CPF ou CNPJ.' It names the specific resource (CNEP) and differentiates from unrelated sibling tools like authenticate and connect.

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 provides operational context: hosted by the platform, no credentials, pay-per-query with prepaid credit, and emphasizes public access data with LGPD responsibility. It does not explicitly state when to use vs alternatives, but no similar sibling tools exist, so the context is clear enough.

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