Skip to main content
Glama

Attestwire

by com.attestwire
OverviewDiscussionsAdmin

Validate an EN 16931 e-invoice

validate_invoice
Read-onlyIdempotent

Validate an invoice, given as a JSON object, against EN 16931 and its national CIUS rule sets (XRechnung UBL/CII, Peppol BIS 3.0, Factur-X). Returns every failure as a "teaching error": the official rule id, the business term (BT-/BG-) it constrains, what the regulation actually requires, and a concrete fix. If the user has an invoice FILE, use validate_invoice_xml instead: retyping a file into JSON loses fields and invents others. Validate before generate_invoice, which refuses an invalid invoice. To explain a rule id you already have, use explain_rule: it is free, and validating again to re-read an error costs a document. REQUIRES AN API KEY and costs 1 document against the monthly quota. Without a key, issue_api_key mints a free one, which works only once the user has saved it, configured it on this server and reconnected.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
invoiceYesThe invoice to validate, as an InvoiceInput object. Required: profile (one of en16931, xrechnung-ubl, xrechnung-cii, facturx-en16931, peppol-bis-3, or "auto" to have it chosen from the buyer: its Leitweg-ID, country and electronic address), invoiceNumber, issueDate ("YYYY-MM-DD"), currency (ISO 4217), seller {name, address{city, postalCode, countryCode}}, buyer {name, address{...}}, and lines[] of {id, description, quantity, unitCode, unitPrice, vatCategory, vatRate}. The XRechnung profiles additionally require buyerReference (BT-10), a seller contact {name, phone, email}, and payment instructions — see BR-DE-1/2/5/6/7/15 via the explain_rule tool. A CREDIT NOTE IS THE SAME OBJECT with invoiceTypeCode (BT-3) set to "381": there is no separate tool and no separate shape, the same rules run, and the amounts stay POSITIVE — the type code is what conveys the direction of the money, so negative amounts on a credit note reverse it back into an invoice. Full schema: https://api.attestwire.com/openapi.json

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • changedInput schema / properties / invoice / description
      Previous value: -"The invoice to validate, as an InvoiceInput object. Required: profile (one of en16931, xrechnung-ubl, xrechnung-cii, facturx-en16931, peppol-bis-3), invoiceNumber, issueDate (\"YYYY-MM-DD\"), currency (ISO 4217), seller {name, address{city, postalCode, countryCode}}, buyer {name, address{...}}, and lines[] of {id, description, quantity, unitCode, unitPrice, vatCategory, vatRate}. The XRechnung profiles additionally require buyerReference (BT-10), a seller contact {name, phone, email}, and payment instructions — see BR-DE-1/2/5/6/7/15 via the explain_rule tool. A CREDIT NOTE IS THE SAME OBJECT with invoiceTypeCode (BT-3) set to \"381\": there is no separate tool and no separate shape, the same rules run, and the amounts stay POSITIVE — the type code is what conveys the direction of the money, so negative amounts on a credit note reverse it back into an invoice. Full schema: https://api.attestwire.com/openapi.json"New value: +"The invoice to validate, as an InvoiceInput object. Required: profile (one of en16931, xrechnung-ubl, xrechnung-cii, facturx-en16931, peppol-bis-3, or \"auto\" to have it chosen from the buyer: its Leitweg-ID, country and electronic address), invoiceNumber, issueDate (\"YYYY-MM-DD\"), currency (ISO 4217), seller {name, address{city, postalCode, countryCode}}, buyer {name, address{...}}, and lines[] of {id, description, quantity, unitCode, unitPrice, vatCategory, vatRate}. The XRechnung profiles additionally require buyerReference (BT-10), a seller contact {name, phone, email}, and payment instructions — see BR-DE-1/2/5/6/7/15 via the explain_rule tool. A CREDIT NOTE IS THE SAME OBJECT with invoiceTypeCode (BT-3) set to \"381\": there is no separate tool and no separate shape, the same rules run, and the amounts stay POSITIVE — the type code is what conveys the direction of the money, so negative amounts on a credit note reverse it back into an invoice. Full schema: https://api.attestwire.com/openapi.json"
  2. First observed

TDQS

A4.6/5.0
Behavior5/5

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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds critical non-obvious behavior: it requires an API key, costs one document against quota, returns failures as 'teaching errors' with specific fields, and clarifies credit note amount polarity. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose, then quickly covers alternatives, prerequisites, and special cases. Every sentence earns its place, providing dense, non-redundant information that is well-organized despite its length.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema, the description covers most critical aspects: purpose, usage alternatives, auth/cost, error return format, and credit note nuances. It does not explicitly state what a successful validation response looks like (e.g., empty list vs. status field), which is a minor gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already fully documents the `invoice` parameter including required fields, formats, enums, and credit note behavior. The description reinforces some points (e.g., positive amounts) but does not add substantial meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Validate an invoice, given as a JSON object, against EN 16931 and its national CIUS rule sets'. It also names the specific rule sets and distinguishes itself from siblings by explicitly pointing to validate_invoice_xml for files and explain_rule for rule explanations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit when-to-use guidance: validate JSON objects, use validate_invoice_xml for files, validate before generate_invoice, and use explain_rule for already-known rule IDs. It also explains cost and key prerequisites for usage.

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

All Attestwire toolsInspect
Try in Browser
One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources