listar_contas

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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so safety is covered. The description's only added value is that balances are as reported by the bank (i.e., live/external data), which is useful context for an open-world tool. It says nothing about authorisation, refresh timing, or whether accounts with no bank connection appear.

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?

A single short clause with no padding. It is efficient, though it reads as a fragment rather than a front-loaded statement of what the tool does.

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?

This is a simple, parameterless read with an output schema and full annotation coverage, so return-value detail is unnecessary. The description tells the agent which account types come back; only the differentiation from saldo/listar_conexoes is missing.

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 takes zero parameters, so there is nothing for the description to compensate for; the baseline for a 0-param schema applies. The mention of which account types are returned is a small extra.

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 names the resource (contas correntes, poupanças, cartões de crédito) and notes the balance is included, but it is a bare noun phrase with no verb — the action ('list') only comes from the tool name. It also does not distinguish this from siblings like saldo or listar_conexoes, which also concern account/balance data.

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?

There is no indication of when to call this instead of saldo (which presumably returns a balance) or listar_conexoes (which presumably returns linked accounts). No prerequisites, no exclusions — the agent must infer selection from the name alone.

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