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 valuable non-schema information: the tool is hosted on the platform, requires prepaid credit per query, does not use platform credentials, queries official Brazilian sources, and includes LGPD data controller responsibilities. This goes beyond annotations, though it doesn't detail edge-case behaviors like invalid input handling.

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 paragraph of about 250 characters, opening with the core purpose ('DER PR: Certidão Negativa de Débitos, consulta em fonte oficial') before adding payment and legal context. It is concise and front-loaded, though it packs several clauses together without structural pauses, making it slightly dense.

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 a simple two-parameter tool with no output schema, the description covers key contextual aspects like pricing, data source, and privacy obligations. However, it omits any explanation of the parameters (how to provide cpf/cnpj) and the expected return format, leaving gaps that could confuse an agent. It is adequate but not fully complete for effortless use.

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 two string parameters (cpf and cnpj) with no descriptions and 0% schema coverage. The description does not mention these parameters at all, failing to explain that they are likely alternatives or what format is expected. Since schema coverage is 0%, the description must compensate but does not, leaving the agent without adequate parameter meaning.

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 explicitly states the tool performs a consultation of 'Certidão Negativa de Débitos' from DER PR, a specific official resource. The verb 'consulta' and the named certificate clearly distinguish it from the generic sibling tools (authenticate, marketplace, etc.).

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 about the tool being a paid, hosted query without platform credentials, but does not explicitly state when to use this over alternatives or any exclusion conditions. The intended use is implied (when needing a negative debt certificate from DER PR), but no direct guidance or alternative comparison is given.

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