Validar linha digitável de boleto

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

With no annotations, the description carries the behavioral burden and does well: it discloses that validation is local/check-digit based and that the bank is not queried. It does not describe error behavior or the exact result format, but an output schema exists to cover return values.

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?

Two sentences, both front-loaded with the essential operation and the key limitation. There is no filler, and the most important constraint (no bank consultation) is stated directly.

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 single-parameter validation tool with an output schema, the description covers what is validated, which formats are accepted, and the major limitation that it does not check payment or due status. Nothing critical is missing for correct invocation.

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 coverage is already 100%, but the description adds meaningful domain constraints: the input must correspond to a 47- or 48-digit linha digitável, depending on boleto type. The schema separately handles punctuation and spacing, so this is a useful complement rather than a repetition.

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 states a specific verb and resource: 'Confere os dígitos verificadores da linha digitável'. It also distinguishes the two supported boleto formats (47 digits for bancário, 48 for arrecadação/convênio), which is more precise than the title alone.

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?

It clearly frames the intended use as checking check digits and explicitly excludes bank lookup, so the agent knows not to use it for payment status. It does not name alternative sibling tools such as validar_documento, but the usage boundary is still clear.

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