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 behavioral context: it is hosted by the platform, requires no platform credentials, is pay-per-use, queries non-confidential citizen-accessible data, and involves LGPD compliance. This goes beyond annotations without contradicting them.

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 compact paragraph with four sentences, each adding distinct information: purpose, hosting/billing, data source/scope, and LGPD. There is slight redundancy ('consulta em fonte oficial' and 'fonte de órgãos oficiais'), but overall it is well-organized and front-loaded with the core purpose.

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 tool is simple (2 optional params, no output schema) and annotations cover safety. The description covers purpose, billing, and legal context, but it lacks specifics on expected output format/fields and does not explain how parameters relate to the query. Given no output schema, more detail on return values and parameter usage would improve completeness.

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 for parameter meaning, but it does not mention CPF or CNPJ at all. The parameter names are self-explanatory to humans, but the description gives no guidance on usage, optionality, or constraints (e.g., whether one or both are needed). This is a significant gap for an agent relying on the description.

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: 'Receita Federal: Radar (Habilitação Comércio Exterior), consulta em fonte oficial.' It uses the specific verb 'consulta' (query) and identifies the resource (Receita Federal Radar). It is distinct from all sibling tools, which are generic platform utilities (authenticate, connect, 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 clear context on when to use the tool: for querying official Brazilian sources as a citizen would. It also specifies operational conditions (no platform credentials, pay-per-query with prepaid credit), which helps the agent select it appropriately. However, it does not explicitly mention alternatives or exclusions, but the context is sufficient given the unrelated siblings.

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