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

The description adds useful behavior beyond annotations: it is paid per query, requires no platform credentials, returns data already available to citizens, and clarifies data-ownership/LGPD responsibility. The read-only, idempotent, and non-destructive traits are already covered by annotations, so this context is sufficient.

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 front-loaded with the core purpose, but it contains redundancy such as 'fonte oficial' versus 'fontes e órgãos oficiais brasileiros' and bundles several legal/payment clauses that could be tightened. It is readable but not maximally concise.

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?

For a one-parameter read-only query, the description offers good operational context around official sourcing, payment, and legal use. However, without an output schema, it does not describe the return shape or result contents, and parameter semantics are largely left to inference.

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%, and the description never explains the 'chassi' parameter, its format, or expected value. The field name and the vehicle-registration context make the parameter somewhat inferable, but the description does not compensate for the missing schema-level explanation.

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 identifies a query operation for SEFAZ MT first vehicle registration ('Primeiro Emplacamento, consulta em fonte oficial') with a specific resource and scope. It also notes that no platform credentials are needed, which helps differentiate it from the generic authentication and platform sibling tools.

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 practical usage context: no platform credentials, prepaid credit required, official Brazilian source data, and LGPD responsibilities. It does not explicitly name alternatives or exclusions, but the sibling tools are unrelated, and this guidance is clear enough for a query tool.

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