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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful behavioral context by enumerating the returned data fields and stating the required CPF and birthdate inputs. It does not mention authentication or error behavior, but the annotation coverage lowers the burden.

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 a single, front-loaded sentence with no filler. Every phrase adds information about purpose, output fields, or required inputs.

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 query tool, the description covers purpose, required inputs, and output fields, and annotations cover safety. However, it omits input formats (e.g., CPF punctuation, birthdate format) and any usage guidance, leaving the agent to guess invocation details.

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 for the two string parameters. It only restates that CPF and birthdate are required, adding no format, validation, or example details beyond what the schema property names already imply.

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 identifies the tool as querying the registration status of a CPF at the Receita and lists the returned fields (name, status, birth, inscription, death). It is specific to CPF and thus distinguishable from sibling consultas_* tools, though it lacks an explicit verb and instead uses a noun phrase.

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 implies usage for CPF registration lookups and states the required inputs ('Requer CPF + data de nascimento'), but it does not explicitly say when to use this tool versus the many sibling consultas_* tools, nor does it mention exclusions or alternatives.

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