List purchase invoices

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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses concrete behaviors: results are returned newest first, filtering supports a defined set of keys, and certain `state` values only apply to purchase invoices and receipts. This adds useful operational context without contradicting any annotation.

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?

The description front-loads the core action and ordering, then compactly lists the filter keys. It is dense but not wasteful; the only minor inefficiency is that it duplicates filter syntax already present in the schema.

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 zero required parameters, full schema coverage, and rich annotations, the tool can be invoked correctly using the description plus schema. The description covers ordering and filter semantics, while the schema covers pagination and administration defaults. It does not describe the return payload, but that is a minor omission for a list operation with no output schema.

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?

The input schema already provides 100% coverage of all parameters, including a detailed explanation of the `filter` syntax, defaults, and valid values. The description repeats the filter keys but does not add meaning beyond what the schema already provides, so the baseline of 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?

The description opens with 'List purchase invoices' and clarifies the resource as 'bills received from suppliers', distinguishing it from sales invoices. It also specifies 'newest first', giving the operation clear scope and a distinct, non-tautological purpose.

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 clearly conveys how to narrow results via the `filter` parameter and lists the supported keys. However, it never explicitly tells the agent when to use this tool over siblings like `get_purchase_invoice` or `list_receipts`, so usage routing is implied rather than explicit.

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