invoices_pdf

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

With no annotations provided, the description carries full burden. It discloses the base64-encoded binary return format with content type (useful behavioral info), the Pro plan requirement, and the generation mechanics (auto on issue or on-demand first request). This is helpful behavioral context beyond what schema/annotations provide.

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 concise sentences with zero waste. The description front-loads the primary action (Download the PDF representation), then adds essential behavioral details (format, plan requirement, generation timing). No fluff or redundant information.

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?

The tool is simple (2 params, no output schema, no nested objects), and the description covers the action, return format, prerequisite (Pro plan), and generation behavior. For a straightforward download tool it's reasonably complete. Slight gap: it doesn't mention error conditions (e.g., not found, premium required) but that's acceptable for this complexity level.

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 coverage is 100% with both parameters (uuid and companyId) documented in the schema itself. The description adds the companyId override behavior context ('uses active company if not set') implicitly, but the schema already documents this. Baseline 3 is appropriate since the description doesn't add much beyond the schema.

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 downloads a PDF representation of an invoice, with a specific verb (Download) and resource (PDF of invoice). It distinguishes from sibling tools like invoices_export_csv, invoices_xml, and proforma_invoices_pdf by being explicitly the PDF download for invoices.

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 on when to use it (download invoice PDFs) and notes the Pro plan requirement as a gating condition. It doesn't explicitly name alternatives or state when not to use it, but the sibling landscape shows distinct PDF tools for proforma and delivery notes, making the intent clear.

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