credit_card_utils

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

With no annotations, the description carries the full behavioral burden but fails to disclose key traits: it does not state whether generated numbers are syntactically valid test data or real card data, whether generation carries rate limits, or what the output/response looks like. For a tool that generates credit card numbers with CVV and expiry dates, omitting whether these are safe/fake values is a meaningful gap.

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 compact sentence that front-loads the resource and then the operation list. Nothing is wasted, though it is arguably too terse given the tool's 11 parameters and multi-operation dispatch surface.

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?

There is no output schema and no annotations, and the description does not explain return values or error behavior for a five-operation dispatcher. The rich schema (5 enums, per-parameter descriptions) covers much of the calling contract, but the description leaves the agent without behavioral or result context.

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 description coverage is 100%, so each of the 11 parameters is already self-documented in the schema, including which operations each applies to. The description adds only the general note that cards come 'com CVV e datas de expiração', which is marginal beyond what the schema provides; baseline 3 applies.

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 a specific resource ('cartões de crédito') and enumerates the five concrete operations (gerar, validar, identificar, formatar, analisar), which map directly to the required 'operacao' enum. It is clearly distinguishable from sibling utility tools like cpf_utils or cnpj_utils, though it never explicitly contrasts itself with them.

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 list of operations implies the contexts in which the tool applies, and the schema's enum descriptions clarify which parameters belong to which operation. However, the description gives no explicit when-to-use, when-not-to-use, or alternative-routing guidance.

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