purchase_order_pdfCall this tool to render one purchase order as an A4 print-ready document and return a download link valid for one hour: the invoice layout titled PURCHASE ORDER, with the buyer and supplier. Pro.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Purchase order id such as PO-2026-0001 | |
| out_path | No | Name for the downloaded file, e.g. acme-credit. Defaults to the document id; the document comes back as a download link valid for one hour |
Changes observed during successful MCP inspections.
Input schema / additionalPropertiesRemoved value: -falseDoes the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this is a non-read-only, non-idempotent, non-destructive, closed-world operation, and the description adds genuinely new behavior: the output is A4 print-ready, the return is a download link, and that link expires after one hour. It does not say whether a file is persisted server-side, which is the main remaining unknown for a write-flagged tool that produces an artifact.
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?
One front-loaded sentence that puts the action, the format, and the return value in a sensible order before the colon. The trailing fragment 'Pro.' is unexplained noise that slightly undercuts an otherwise tight definition.
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 two-parameter render tool with full schema coverage and no output schema, the description covers format, layout contents (buyer and supplier), and link lifetime, which is close to everything an agent needs. Only the persistence/regeneration story is missing.
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 both 'id' (example PO-2026-0001) and 'out_path' (filename, defaults to document id) already documented inline. The description only repeats the one-hour download-link detail for the output rather than clarifying parameter behavior, 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 ('render one purchase order as an A4 print-ready document') plus the concrete outcome ('return a download link valid for one hour'), which distinguishes it from purchase_order_get and purchase_order_text by output format. It stops short of naming those siblings, so the differentiation is inferential rather than explicit.
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?
'Call this tool to render...' implies the usage condition (you need a printable/downloadable PDF of a single PO), but there is no explicit when-not guidance and no named alternative for the text or JSON views despite three sibling tools covering those shapes. An agent can infer the choice but must do the work itself.
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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