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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile needs no repetition. The description adds genuine value beyond them: it enumerates the state machine values (ausente, verificando, ativa, congelada; configurando, perguntas, pronto), which is the actual behavior an agent must interpret.

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?

Two sentences, front-loaded with what is returned and followed by the routing advice; nothing is redundant. The parenthetical state enumerations are dense but each value carries decision-relevant information for the agent.

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 must carry the return shape, and it does by naming every field and its possible states. It is complete enough to call and interpret, with the only gap being the unresolved overlap with `status`/`situacao_credencial`.

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?

The tool takes zero parameters, so there is no parameter semantics to convey and the baseline of 4 applies. The description correctly spends no words on arguments.

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 enumerates exactly what the tool returns: CNPJ, name, credential state, onboarding state, import and warnings, which is a precise resource statement. It is distinguishable from configurar_credencial and responder_perguntas_fiscais, but it never explains how it differs from the sibling tools `status` and `situacao_credencial`, which likely overlap heavily.

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?

"Comece por aqui" gives an explicit entry-point instruction, and the conditional branches (credential absent → configurar_credencial; pending questions → responder_perguntas_fiscais) route the agent correctly. What's missing is guidance on when to prefer this over `status` or `situacao_credencial` for credential information.

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