ar_cuitValida formato y dígito verificador de un CUIT o CUIL (11 dígitos). No consulta a AFIP/ARCA.
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"cuit": "<cuit>"
},
"name": "ar_cuit"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| cuit | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose the most important behavioral trait: this is a pure local format/check-digit validation with no external AFIP/ARCA call, implying no auth, no rate limit, and no side effects. It does not state what the response looks like on success vs. failure, which is the remaining 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?
Two sentences, no filler, with the core function first and the key limitation second. Every clause earns its place.
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, side-effect-free validator with no output schema, the definition covers purpose, scope, and the non-network behavior. The only omission is the return semantics (e.g., boolean valid flag vs. error detail), which an agent would benefit from knowing since no output schema exists.
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 0% (the 'cuit' string has no description) and the schema even permits up to 32 characters, so the description's 'CUIT o CUIL (11 dígitos)' is the only source of the real content constraint. That compensates well for the coverage gap, though it does not spell out accepted formats (hyphens, spaces) or the expected check-digit algorithm.
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+resource ('Valida formato y dígito verificador de un CUIT o CUIL') and pins the scope with '(11 dígitos)' and 'No consulta a AFIP/ARCA'. An agent can distinguish this local validator from any real registry lookup without opening the schema.
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 phrase 'No consulta a AFIP/ARCA' tells the agent this is an offline, self-contained check rather than an authoritative lookup, which is the key selection criterion. It stops short of naming an alternative for when authoritative verification is actually needed, so it is clear context but not full when/when-not routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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