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

Annotations already indicate this is a mutating, non-idempotent operation, so the description is not required to restate that. It adds useful context: the registration is for later reconciliation and has no cost. However, it does not explain side effects, duplication behavior, or what happens after a successful registration.

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 extremely concise: two short sentences with no filler. The core action and purpose are front-loaded, and the additional cost note is relevant and compact.

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 low-complexity tool with only two required parameters and no nested objects, the description gives enough surface-level context to attempt a call. However, it omits any guidance on what 'referencia' means, what a successful response looks like, and any edge conditions around the amount, making it only minimally complete.

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 0% and the description does little to clarify the two parameters. 'Monto' can be reasonably inferred as the amount of the receivable, but 'referencia' is ambiguous: it could be an invoice number, customer reference, or internal ID, and no format or uniqueness requirements are given.

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 a specific verb ('Registra') and resource ('obligacion (cuenta por cobrar)'), and adds the purpose of later reconciling against a payment. This strongly differentiates it from the sibling tools, which are mostly consultar/validar/calcular operations.

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 provides clear context: use this tool when you need to register an accounts-receivable obligation that will later be reconciled with a payment. It does not explicitly name alternatives or state when not to use it, so it falls short of a full 5.

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