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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description adds valuable behavioral context beyond that: it clarifies that the tool does not regenerate a QR, transfer funds, or confirm payment, and warns to check amount/network/recipient. This enriches the agent's understanding of side effects and safety.

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 concise sentences with zero filler. The primary action and scope are front-loaded, followed by exclusions and a safety reminder. Every sentence earns its place and the description is immediately scannable.

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-parameter tool with a rich output schema and safety annotations, the description is complete. It covers the action, scope, exclusions, and a caution, and the output schema handles return values. Nothing an agent needs to call it correctly is missing.

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 schema provides only the id parameter with format constraints but no semantic meaning. The description fills this gap by indicating the id refers to an owned payment request, giving the agent the necessary context to supply the correct identifier. With 0% schema coverage, this semantic addition is essential and well done.

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 a specific verb (Download) and a specific resource (original stored QR image for one owned payment request). It also distinguishes itself from siblings by explicitly listing what it does not do (regenerate, transfer, confirm), making it unambiguous which tool to pick.

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 implies when to use the tool (when you need the original stored QR) and includes a safety caution to verify details before paying. However, it does not explicitly name alternative tools or conditions for choosing this over auraspay_payment_get or auraspay_payment_create, so it falls slightly short of full guidance.

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