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

Given annotations that are all false and unhelpful, the description carries the burden of behavioral disclosure. It adds valuable details: the generated text includes specific sections, a one-hour-valid .txt download link is produced, and the feature is free on every tier. It does not explicitly address side effects or authentication, but nothing suggests destructive 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?

The description is two sentences with no wasted words. The core purpose and output content are front-loaded, followed by the time-limited download link and pricing note, both of which add contextual value.

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 no output schema, the description compensates by explaining exactly what the agent will receive: a plain-text order with line table, VAT lines, total, and supplier instructions, plus a one-hour .txt link. This is sufficient for an agent to use the tool correctly, though it does not detail the exact response envelope.

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 with descriptions for id, greeting, and sign_off, including the PO id format and defaults. The description adds no parameter-specific meaning, so the baseline of 3 is appropriate.

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 states a specific verb and resource: 'Turn a purchase order into a plain-text order to paste into an email.' It enumerates the expected content (line table, VAT lines, total, delivery date, PO number) and clearly differentiates from the sibling purchase_order_pdf by emphasizing plain-text email output.

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 for when to use the tool: when a plain-text purchase order is needed for pasting into an email. It does not explicitly name alternatives or exclusions, so it stops short of a 5, but the intended use case is unambiguous.

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