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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, not open-world), so the bar is lower; the description still adds real behavioral value by disclosing the result caps (up to 20 addresses and 20 companies), the quota exemption, and the fact that the origin's protection limit applies.

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?

Three compact clauses, front-loaded with the core purpose before the quota and limit caveats. Only minor friction from unexplained internal jargon ('pontos_total', 'the origin's protection limit').

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?

There is no output schema, so naming the `pontos_total` field and the caps on returned addresses/companies is genuinely useful. Quota and limit caveats round it out; only the sibling differentiation and any error/empty-result behavior are missing.

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?

There is only one parameter and schema coverage is 100%, so the schema fully documents that 'cep' accepts input with or without a hyphen. The description adds nothing about the parameter format, which is the expected baseline when the schema does the work.

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+resource: retrieve addresses and companies at a Brazilian CEP. Clear enough to act on, but it never distinguishes itself from near-name siblings like consulta_cep or consulta_cnpj, so an agent cannot tell from the description alone which of the CEP/CNPJ tools to pick.

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?

It implies a use case (looking up addresses/companies for a postal code) and adds quota-relevant context ('without counting against the daily free limit'), but gives no explicit when-to-use vs. when-not, and no guidance on choosing it over consulta_cep or consulta_cnpj.

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