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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the tool is clearly non-destructive. The description adds context about being hosted on the platform, no platform credentials required, payment via prepaid credit, and data control under LGPD, which provides some behavioral context. However, it doesn't elaborate on return structure or error scenarios.

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, reasonably concise paragraph that conveys purpose, source, payment, and data responsibility. It front-loads the main purpose but could be more structurally clear, though it is not overly long.

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 the tool's complexity (low complexity, no output schema, three optional parameters), the description covers purpose, data source, and legal responsibilities, but lacks parameter semantics and usage guidelines. It is adequate for a simple consultative tool but leaves gaps in parameter usage.

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. It mentions the certificate consultation but doesn't explain the three parameters (cpf, cnpj, contribuinte) or their roles. The description doesn't clarify which parameter is required or how they relate, leaving the agent without sufficient semantic guidance beyond the schema names.

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 states the tool performs a consultation of 'Certidão Negativa de Débitos' (negative debt certificate) from an official source for Prefeitura MG Luz, which is a specific verb+resource. It distinguishes from siblings by referencing the official source and the certificate type, though it doesn't explicitly name an alternative tool.

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 consulting official Brazilian public data (same available to citizens) and mentions payment with prepaid credit, but it doesn't explicitly state when to use or when not to use this tool versus alternatives. It lacks explicit exclusions or alternatives.

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