get_invoice_pdf

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

With no annotations, the description carries the full burden and does substantial work: it discloses that the default is an inline base64 payload, that supplying output_path causes a filesystem write, and that writes are gated by the QBO_PDF_OUTPUT_DIR allowlist with path-resolution enforcement. It omits error behavior for invalid/unauthorized invoice IDs and permission requirements, which keeps it below a 5.

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 sentences, each earning its place: purpose first, default return mode second, conditional disk-write behavior and its constraint third. No filler, no repetition of the tool name, and the most important selection-relevant fact (inline by default) is front-loaded.

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 single-resource download tool with no annotations and no output schema, the description adequately covers what is returned and what side effects occur. The remaining gaps are minor but real: it does not state that invoice_id is required, nor what an agent should expect on failure (invalid ID, path outside allowlist, existing file without overwrite).

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 reported as 0% at the top level, but the description compensates by defining what output_path does and what happens when it is absent, plus the allowlist constraint governing the resolved path. The overwrite flag is covered only in the schema, and invoice_id is never described in either place, so the meaning of a required parameter remains unstated.

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 gives a specific verb and resource ('Download a QuickBooks Online invoice as a PDF') and states the output format, so an agent immediately knows this is a rendering/download tool rather than a data fetch. It does not explicitly differentiate itself from the sibling read_invoice, which retrieves invoice data as JSON, leaving that contrast to inference.

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?

It clearly explains the two modes of use — omit output_path for inline base64, supply it to write to disk — including the prerequisite environment variable. It stops short of explicit when-not guidance (e.g., 'use read_invoice for structured invoice fields'), so the routing decision against alternatives is still partly inferred.

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