Return the PDF of a document (invoice, proforma invoice, receipt, order, or notice) as a base64-encoded string. The caller can decode the base64 and save it as a .pdf file. Defaults to document_type "invoice".
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Document ID | |
| document_type | No | Document type: invoice (default), proforma_invoice, receipt, order, notice |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden. It does disclose the non-obvious output shape (base64 string, intended for decoding to a .pdf) and the default type, but says nothing about failure modes, whether id must belong to the selected document type, auth requirements, or document size.
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, front-loaded with the return type and resource, with zero filler. The final sentence restates information already present in the schema's document_type description, a minor redundancy.
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 only two flat parameters, no output schema, and no nested objects, the description covers what an agent needs: the resource, the return encoding, and the type default. Remaining gaps (id must match the chosen document type, error behavior) are minor for a straightforward 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%, so baseline is 3. The description repeats the enum of document types and the 'invoice' default that the schema already documents and adds no syntax, format, or cross-parameter constraint beyond it.
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 ('Return the PDF of a document') plus its serialization ('base64-encoded string') and enumerates the five supported document types, so an agent can distinguish this PDF-fetch tool from metadata siblings like get_invoice. It never names a sibling explicitly, so differentiation is inferred rather than stated.
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 implies the use case ('The caller can decode the base64 and save it as a .pdf file') and states the default document_type, which is genuine usage context. However, it gives no explicit when-to-use/when-not guidance, no pointer to get_invoice for metadata instead of a file, and no note about matching the id to the right document_type.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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