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

With no annotations, the description carries the full behavioral burden. It implies a read-only balance lookup but never states this, nor whether it requires authorization, whether it can fail for accounts without the optional modules, or how those conditional modules affect the response. Only the conditional content hint adds any value.

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 sentence that is front-loaded with the primary content ('Saldos de la cuenta'), but the trailing conditional clause about optional modules is vague and slightly obscures rather than sharpens the purpose.

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 no-parameter, no-annotation, no-output-schema tool, the description names the general content but does not describe the shape of the result or the conditions under which the optional sections appear. It is minimally adequate rather than complete.

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 schema has zero parameters, which is the baseline-4 case: there is nothing parameter-wise for the description to explain or compensate for.

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 says what the tool surfaces — account balances, document credits, and optionally biometric/WhatsApp/SMS verification status — so the resource is identifiable. But it has no verb, and the conditional 'si la plataforma los usa' muddies what will actually be returned. It does not differentiate itself from siblings like traza_auditoria or listar_documentos, though the resources differ obviously.

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 guidance on when to call this versus the sibling tools, no preconditions, and no mention of scope (own account vs. another). The agent must infer that this is a status/balance lookup available at any time.

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