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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the scope (user's own banks/accounts) but no additional behavioral details such as sorting, pagination, or whether closed accounts are included. It neither contradicts annotations nor enriches them significantly.

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 short sentence in Portuguese, conveying the complete purpose with no wasted words. Every word earns its place, making it extremely concise and well-structured.

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?

For a simple zero-parameter list tool with strong safety annotations, the description is adequately complete. It states what is listed (banks/accounts of the user), and no output schema exists, so the return value is implicitly the list itself. Some details like account types or balance inclusion are absent, but they are not essential for this level of complexity.

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 has zero parameters, so there is no parameter burden. The schema coverage is 100% (trivially). For zero-parameter tools, the baseline is 4, and the description does not need to add parameter meanings. It remains neutral.

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 a specific verb ('Lista' / lists) with a clear resource ('os bancos/contas do usuário' / the user's banks/accounts), which clearly differentiates it from sibling tools like poupa_cards, poupa_get_balance, and poupa_retrieve_transactions. The purpose is unmistakable.

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 implies usage: use this tool when you need to list the user's banks/accounts. However, it does not explicitly state when to use this over alternatives, nor does it mention exclusions or provide context about related tools. The guidance is minimal but not misleading.

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