validar_cst

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

No annotations are provided, so the description carries full transparency burden. It discloses offline behavior ('valida contra tabelas em memória; não requer conexão') and parameter details, but doesn't mention potential return format or error handling.

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?

The description is well-structured, front-loading purpose and usage. It is slightly verbose but each sentence adds value, covering offline behavior, parameter instructions, and digit validation rules.

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?

Given the tool's simplicity (2 params, offline validation), the description is fully complete. It covers when to use, parameter guidelines, offline behavior, and the output schema existence covers return values.

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 100%, and the description adds significant value beyond the schema by explaining digit lengths ('3 dígitos para CST ICMS', '2 dígitos para CST PIS/COFINS/IPI', '3 dígitos para CSOSN') and providing examples ('ex: "000", "040"').

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 clearly states the tool validates CST/CSOSN codes, with specific examples and context (NF-e, SPED). It distinguishes well from sibling tools, as no other sibling appears to focus on CST/CSOSN validation.

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 description explicitly states when to use: 'ao preencher o campo CST/CSOSN na NF-e ou no SPED EFD'. It lacks explicit when-not-to-use or alternatives, but the specific context makes the usage clear.

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