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

With no annotations provided, the description carries the burden of conveying the read-only nature via 'List' and 'Shows', and transparently lists the key output fields. This is sufficient for a simple no-parameter list tool, though it does not mention potential pagination or sorting behavior.

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 short sentences deliver all necessary information with no filler or redundant phrasing. The description is front-loaded with the primary action and scope.

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 simple zero-parameter list tool, the description fully covers purpose and output fields. It lacks only optional details like result ordering or pagination, but these are not essential for basic invocation.

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 tool has no parameters, so the input schema is trivially complete. The description adds value by clarifying the output scope and fields, which is enough given the zero-parameter design.

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 uses a specific verb ('List') and precise resource ('purchase orders for this account'), clearly distinguishing it from sibling tools like payouts or earnings. It also specifies the returned data types (status, book titles, amounts, timestamps).

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 states the tool's scope ('all purchase orders for this account') and purpose, implying when to use it. It does not explicitly mention alternatives or exclusions, but the context is unambiguous for a list operation.

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