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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description complements this by adding cost-per-query, no platform credentials required, and LGPD data control obligations. It reinforces the read-only nature and adds operational context without contradicting any annotations.

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 concise paragraph that front-loads the purpose, then adds payment and legal context. Each sentence contributes useful information, though the legal disclaimers could be seen as slightly overlong, but they are relevant to responsible use.

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?

Despite good coverage of the tool's purpose and compliance aspects, the description omits any guidance on parameter semantics or expected input values. With 12 parameters and no output schema, this is a significant gap that leaves the agent unable to construct valid requests.

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 schema has zero parameter descriptions and the tool description provides no explanation of the 12 parameters (e.g., pkcs12_cert, numero_recibo, data_final_apuracao). The agent is left with no guidance on how to populate required fields, making the tool effectively unusable without external knowledge.

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 performs consultations (consulta) on official Brazilian DCTF data via the ECAC system. It distinguishes itself from generic sibling tools (authenticate, connect, etc.) by specifying the domain and resource, and notes it provides the same non-confidential information available to citizens.

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 for when to use the tool (consulting DCTF data from official sources) and mentions practical details like prepaid credit and LGPD responsibilities. However, it does not explicitly state when not to use it or name alternative tools, though siblings are not directly comparable.

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