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

Annotations declare read-only, idempotent, and non-destructive behavior, and the description adds useful context beyond these: payment per query, no platform credentials required, data is non-confidential, and LGPD compliance responsibilities. This enriches the agent's understanding without contradicting 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 paragraph and reasonably brief, but it includes legal disclaimers (LGPD) and hosting/payment details that are tangential to core usage. It is not overly verbose and front-loads the main purpose, though some content could be trimmed.

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 absence of an output schema and the complete lack of parameter descriptions, the description does not adequately explain what the tool returns or what inputs are required beyond their names. An agent would struggle to know what to pass for 'inscricao_municipal' or 'chave_identificacao', making the tool incomplete for practical 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 input schema has three required string parameters (inscricao_municipal, numero_nota, chave_identificacao) with zero description coverage. The tool description does not explain what these mean or how they map to an NFS-e query, leaving the agent without guidance on how to populate them.

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 function: querying NFS-e (electronic service invoice) from the official source of Prefeitura MT Cuiabá. The specific verb 'consulta' and resource 'NFS-e' distinguish it from sibling tools, which are generic platform utilities.

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 context about when to use it (to query official Brazilian sources) and notes it requires prepaid credit, but it does not mention alternatives or explicitly state when not to use the tool. It implies usage for NFS-e queries but lacks exclusion criteria.

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