invoices_xml

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses the return payload ('XML text content') and the conformance standards (CIUS-RO, EN 16931), which tells the agent the output is submission-ready rather than arbitrary XML.

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 sentences, zero filler, with the core action and format front-loaded before the standards detail. Everything 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?

With no output schema, the description correctly covers the return value ('XML text content'), which is the key unknown. It does not address whether the invoice must already be issued/validated or what happens on an invalid state, a minor gap for a simple read tool.

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 100% with only two parameters, so the schema already documents uuid and the companyId override. The description adds nothing about parameter behavior (e.g., whether the active company is used when companyId is omitted), so it sits at the baseline.

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 (download XML file for an issued invoice) and pins the exact format (UBL 2.1). It does not name or differentiate against close siblings like invoices_export_efactura_zip or invoices_efactura_message, so an agent must infer which export tool fits.

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 'for an issued invoice' implies a precondition and usage context, but the description never says when to pick this over invoices_pdf, invoices_export_efactura_zip, or invoices_submit. No exclusions or alternatives are mentioned.

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