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

With no annotations, the description carries the full burden. It states the operation (lists holidays) and requires the IBGE code, but does not disclose return format, error handling, default behavior for optional parameters, or any limitations (e.g., valid years). It adds some context with examples but lacks richer behavioral details for a tool with no structured 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 concise and well-structured: a clear first sentence stating purpose, a usage trigger, a requirement note with an alternative tool, and concrete examples. Every sentence earns its place, with no fluff or repetition.

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 a simple list operation with 4 parameters and no output schema. The description adequately covers the main purpose, usage context, and prerequisite (IBGE code). However, it does not describe the output structure or default behavior (e.g., year default), which would be helpful given the absence of an output schema, but this is a minor gap for a straightforward list 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 coverage is 100%, so the baseline is 3. The description adds value beyond the schema by providing concrete IBGE code examples for major cities and reiterating the need to use 'buscar_municipios' when the code is unknown. This reinforces the 'ibge' parameter semantics, though it does not add much for 'ano', 'bancarios', or 'facultativos'.

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 a specific verb and resource: 'Lista todos os feriados de uma cidade brasileira' (lists all holidays of a Brazilian city). It distinguishes this tool from siblings by specifying the scope (city-level, including national, state, and municipal holidays) and by providing usage context for city-specific queries.

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?

It explicitly says when to use this tool: 'Use quando o usuário perguntar sobre feriados em uma cidade específica.' It also gives a clear alternative workflow: if the IBGE code is unknown, use 'buscar_municipios' first. However, it does not explicitly contrast with sibling tools like 'feriados_nacionais' or 'feriados_por_estado', so it lacks a full when-not guidance.

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