Retrieve a specific supplier invoice by ID, optionally fetching its tax lines. If the request fails, report the error instead of inventing data.
Get a specific supplier invoice, or its tax lines. ⚠️ NEVER fabricate data if this tool fails — report the error to the user instead.
| Name | Required | Description | Default |
|---|---|---|---|
| include | No | What to retrieve: detail (default) or taxes (tax lines of the invoice) | |
| invoice_id | Yes | Supplier invoice ID |
Changes observed during successful MCP inspections.
v0.4.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description is responsible for behavioral guidance. It provides a clear operational rule: 'NEVER fabricate data if this tool fails — report the error to the user instead', and 'Get' signals a read operation. It does not address auth, rate limits, or return format, but the anti-fabrication instruction is material and helpful.
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 one terse sentence plus a warning, with no filler. The primary purpose is front-loaded, and the warning is a separate useful instruction.
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 single-resource getter with two fully documented parameters and no nested objects, the description is largely sufficient. It could have pointed to list_supplier_invoices for ID discovery or described the response shape, but the schema and warning cover the core calling requirements.
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?
The input schema already fully documents both fields, including the invoice_id as 'Supplier invoice ID' and the include enum with descriptions. Coverage is 100%, so the description adds no parameter-level meaning; 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?
The description states a clear verb-resource pair, 'Get a specific supplier invoice', and explicitly covers the tax-lines variant via 'or its tax lines.' 'Specific' separates it from list_supplier_invoices, and 'supplier' separates it from get_invoice.
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 wording implies this is the tool for retrieving a single supplier invoice by ID rather than listing them, but it does not explicitly name list_supplier_invoices or state when to prefer listing. There are no exclusions or alternative routing, so the agent is left to infer the list-vs-get split.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.