Plano e saldo de créditos

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds genuinely new context beyond that: the call requires a BITBUSCA_API_KEY and belongs to the 'Avançado' tier, which an agent needs to know before invoking it.

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 well-formed sentence with the prerequisite front-loaded in brackets, so the constraint is seen before the purpose. No wasted wording, though brevity means some context is left implicit.

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, no-parameter read tool whose annotations fully cover the safety profile and whose schema is empty, the description supplies everything essential: purpose, auth requirement, and tier. The absence of an output schema is minor since the description enumerates what is returned (plan, balance, limits).

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 disambiguate; the baseline for a no-param tool applies. Nothing in the description misrepresents the input surface.

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?

States a specific verb ('Mostra') and three concrete resources: plan, credit balance, and key limits. It is easily distinguished from the sibling tools, which are all document/legal lookups, though it doesn't name an alternative explicitly.

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 bracketed '[Avançado: exige BITBUSCA_API_KEY]' gives a useful prerequisite (advanced tier, API key needed) that implicitly tells the agent when this tool is callable. However, there is no explicit when-to-use/when-not guidance or pointer to a sibling such as como_ativar_avancado for key setup.

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