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

The annotation readOnlyHint=true already covers the safety profile. The description adds useful scope context ('all accounts'), but does not disclose any additional behavioral traits such as default behavior when no empresaId is provided, return format, or potential limitations. This is consistent with 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, clear sentence that is perfectly sized for the tool's simplicity. It conveys the purpose without any wasted words, and the key information is front-loaded.

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 simple, but there are gaps: the empresaId parameter is optional, yet the description doesn't clarify what happens when it's omitted (e.g., which company's balance is returned). There is no output schema and the return structure is not described. For a query tool, this leaves some ambiguity, though the core function is clear.

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% (empresaId is described as 'ID da empresa'), so the description doesn't need to explain parameters. The description implies the parameter is used to select the company, but adds no extra meaning beyond the schema.

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 uses the specific verb 'Retorna' (returns) and clearly identifies the resource: 'o saldo atual de todas as contas bancárias da empresa' (current balance of all company bank accounts). This distinguishes it from sibling tools like listar_contas_bancarias, which likely list account details rather than balances.

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 makes the use case clear: this tool answers the question 'what is the current balance of all company accounts?'. It doesn't explicitly name alternatives or exclusions, but the context is sufficiently clear for an agent to select it when a balance query is intended, especially given the tool's name.

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