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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the description does not need to repeat that. It adds useful context about payment per query, no platform credentials needed, and LGPD compliance. However, it does not describe the exact response format or any limitations beyond what annotations provide.

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 concise and front-loaded with the key purpose. It includes necessary context about payment and LGPD in a few sentences. However, it could be slightly more structured, but overall it is efficient and avoids unnecessary verbosity.

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?

Given that the tool has three parameters (likely alternative identifiers), no output schema, and annotations only provide read-only and idempotent hints, the description covers the basic purpose and payment model. However, it lacks details on which parameter should be used depending on the user type (PF or PJ), and it does not mention anything about response structure or error conditions. For a simple read-only query tool, this is adequate but not comprehensive.

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 input schema has three parameters: cpf, cnpj, and inscricao_mobiliaria, but no descriptions. The description does not elaborate on any of these parameters, leaving the agent to infer that they are alternative identifiers (CPF for individuals, CNPJ for companies, and municipal registration). Since schema coverage is 0% and the description adds no parameter-specific information, the agent must rely on the parameter names alone, which is somewhat clear but incomplete.

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: consulting Certidão Negativa de Débitos (negative debt certificate) from the official source of Prefeitura de Joinville. It specifies the resource (the certificate) and the action (consult), and distinguishes it from other tools in the context.

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 context that this tool accesses official Brazilian sources, is hosted on the platform, and requires prepaid credits. It implies when to use it (to check for debts with Joinville municipality) and mentions that it does not require platform credentials. However, it does not explicitly state when not to use it or mention alternative tools for other municipalities or certificates.

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