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

Annotations already declare destructiveHint=true, so the description's added value is the eligibility rule and the regulatory reason (the facturado chain) plus a return value. It doesn't cover error behavior (e.g. what happens if the id is a finalized invoice or does not exist), which is the remaining gap for a destructive operation.

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 sentences, front-loaded with the action and scope, then the constraint and alternative, then the return value. Every sentence carries distinct information with no repetition.

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 one-parameter destructive tool, the description covers eligibility, the safe alternative, id provenance, and the return value; with no output schema, stating the return is a plus. Only failure modes for an invalid or finalized id are unaddressed.

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 single parameter already documents 'invoice id from list_invoices'. The description's 'by id' and 'use list_invoices to find the id' restate the schema rather than adding format, type, or validation detail, 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 plus a hard scope qualifier: 'Delete a DRAFT invoice by id.' The DRAFT restriction immediately separates it from cancel_invoice and rectify_invoice in the sibling set.

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?

Explicit when-to-use (drafts only) and when-not-to-use (finalized invoices in the Veri*factu chain), naming the correct alternative rectify_invoice. It also routes the agent to list_invoices for id discovery, leaving nothing to inference.

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