Save an invoice PDF

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

With no annotations, the description carries full burden. It discloses the tool is read-only, saves to an allowlisted directory, and does not alter the invoice's send state. Some behavior like error handling or directory creation is not detailed, but the key safety and I/O traits are covered.

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?

Two sentences with no extraneous words. The first sentence states the main action and condition, the second adds safety behavior. Perfectly concise for the tool's simplicity.

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 tool with no output schema, the description covers purpose, safety, and constraints. The missing aspect is whether the invoice must be in a certain state (e.g., already sent) for PDF generation, but overall it provides enough context for reliable use.

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?

Both parameters have schema descriptions, and the description adds the critical constraint that the directory must be from the SEVDESK_RECEIPT_DIRS allowlist, which goes beyond the schema's definition of 'Absolute path of an allowlisted directory.' This extra context aids correct invocation.

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 clearly states the tool fetches and saves an invoice PDF to an allowlisted directory. The verb 'fetch' and resource 'invoice PDF' are specific, and the tool distinguishes itself from siblings like sevdesk_list_invoices and sevdesk_create_invoice which handle listing and creation.

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 provides clear context by stating it is read-only and never changes the invoice's send state. While it does not explicitly list alternatives, the context is sufficient for an agent to understand when to use this tool (to download a PDF) versus other invoice-related tools.

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