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

Beyond the readOnly and idempotent annotations, the description discloses several behavioral aspects: it is hosted by the platform, requires no credentials, operates on a prepaid credit system, and clarifies data sensitivity (non-confidential) and LGPD compliance responsibilities. This adds significant transparency about pricing, authentication needs, and data governance, exceeding the annotation-only baseline.

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 contains redundancy, e.g., repeating 'consulta em fonte oficial' and 'consulta informação de fontes e órgãos oficiais'. It also includes legal jargon (LGPD) that could be condensed. While not excessively long, it is wordier than necessary and could be streamlined for clarity.

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?

The description covers many important contextual aspects: official source, payment model, credential requirements, data sensitivity, and LGPD responsibility. It does not describe the return format, but since the tool is clearly for obtaining a certificate, the output is implied. Given the tool's simplicity, this level of detail is largely complete, though it could be enhanced by specifying expected output or any prerequisites.

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 description gives no explanation of the parameters (ie, cpf, cnpj). Schema coverage for parameter descriptions is 0%, so the description was expected to compensate. It does not mention what each identifier stands for or when to use which. The only hint is the tool name itself, which implies tax-related identifiers, but no explicit mapping is provided. This leaves the agent without guidance on parameter selection.

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: it queries an official source for a negative debt certificate (Certidão Negativa de Débitos) from SEFAZ MS. This is a specific verb ('consulta') and resource, and it distinguishes itself from sibling tools like 'authenticate' or 'connect' which serve different functions.

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 useful usage context: it is a paid service (requires prepaid credits), requires no platform credentials, and is used for querying official Brazilian sources. While it does not explicitly mention alternatives (none exist among siblings), it implies the appropriate scenario—when a user needs official tax certificate data without additional authentication. This is more informative than the mid-example but lacks explicit 'when to use' or 'when not to use' guidance.

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