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

Annotations are sparse (only openWorldHint), so the description carries the burden of behavioral disclosure. It adds useful context about grouping behavior and mandatory usage, but does not explain post-emission behavior, return values, or failure modes. The openWorldHint already signals side effects, but the description adds only limited extra behavioral detail.

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 compact and front-loaded, with two sentences that each add value: the first defines the action and purpose, the second states a key usage condition. No wasted words or redundancy.

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?

Given the tool's high complexity (24 parameters, nested structures) and low schema coverage, a two-sentence description is inadequate. It fails to mention prerequisites like referencing existing CT-e/NF-e keys, how to structure the grouped documents, or important environmental parameters like tipoAmbiente. The presence of an output schema reduces the burden for return values, but the description still lacks sufficient guidance for safe and correct invocation.

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 tool description contains no parameter information whatsoever. With schema description coverage at only 42%, the description needed to compensate for the many undocumented parameters (e.g., lote, serie, codigo, numero, carregamentos, descarregamentos), but it does not. This is a critical gap for such a large parameter set.

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 the specific action ('Emite MDF-e') and resource (Manifesto Eletrônico de Documentos Fiscais), and explains it groups multiple CT-e/NF-e into a single transport. This differentiates it from sibling emission tools like cte_emitir and nfe_emitir.

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 an explicit when-to-use condition: 'Obrigatório para transportadores com vários DFs no mesmo veículo.' However, it does not name alternative tools or state when not to use it, so it falls short of a 5.

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