textokit_cuit_ar

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

With no annotations, the description carries the full burden and does disclose the critical operational trait: 0.001 USDC per call charged via x402 on Base from the caller's wallet, so the agent knows payment/auth is required. It doesn't describe the pass/fail response shape or how malformed input is handled, leaving a moderate 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?

Three short clauses: purpose first, cost second, free alternative last. No filler, and the most decision-relevant facts are front-loaded.

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 2-parameter validator with no output schema, the essential facts (what is validated, cost, payment rail, free sample) are present. The one missing piece is what a successful call returns, which an agent must infer.

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 enum for type plus the identifier format rules are already documented in the schema. The description only hints at the check-digit concept and adds no format or defaulting detail beyond structured fields, so 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?

States a specific verb and resource ('Validate Argentine CUIT or CUIL tax id') plus the concrete scope of checks ('check digit'), and names the KYC onboarding use case. It is unmistakable against siblings like textokit_direcciones_ar or textokit_dev_utils.

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?

Points the agent at textokit_sample as a free alternative before paying, which is real routing guidance. It does not state exclusions (e.g. what to do for non-Argentine IDs or when validation should be skipped), so it stops short of a full when/when-not rule set.

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