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

No annotations are provided, so the description carries the full burden. It adds the behavioral detail that the result includes national plus state holidays for the given UF, which is useful. However, it does not disclose any side effects, prerequisites, default behavior (e.g., if ano is omitted), or output format, leaving some gaps for a listing tool.

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 three sentences: the action, the usage instruction, and the acronym list. It is front-loaded with the core purpose, contains no redundant information, and every sentence earns its place. The UF list, while long, is necessary for correct parameter use and is compactly formatted.

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 description covers the essential purpose and usage context, while the schema provides comprehensive parameter details (100% coverage). However, without an output schema, the description does not describe the return structure, and it doesn't mention parameter interactions beyond what the schema provides, which would be helpful for a 4-parameter tool. Overall, it is sufficient for a straightforward listing tool.

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 100%, so the baseline is 3. The description adds a complete enumeration of valid UF acronyms ('AC, AL, AP, AM, BA...'), which goes beyond the schema's example-based description and directly aids the agent in selecting valid values for the required 'uf' parameter.

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 action and resource: 'Lista todos os feriados de um estado brasileiro (feriados nacionais + estaduais daquele UF)'. This specifies a specific verb ('Lista'), a resource ('feriados de um estado'), and scope ('nacionais + estaduais'), clearly distinguishing it from sibling tools like feriados_nacionais and feriados_por_cidade.

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 explicitly instructs when to use the tool: 'Use quando o usuário perguntar sobre feriados em um estado específico', with concrete examples like 'feriados em São Paulo'. It does not mention exclusions or alternative tools, but the clear context is sufficient to avoid confusion with national or city-specific holiday tools.

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