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

Annotations already flag destructiveHint=true and readOnlyHint=false, but the description adds genuinely new context: that this reverses a purchase and that approval is not guaranteed and depends on carrier/label age. It does not say what the returned refund state looks like or whether repeat calls are safe, but the non-deterministic outcome is the key trait an agent needs.

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 compact clauses with no waste; the action, the risk warning, and the endpoint are each front-loaded in order of importance for an agent deciding whether to call it.

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 destructive mutation with no output schema and no annotations gap, the description covers purpose, risk, and endpoint. What is missing is only the shape of the outcome (e.g., pending-refund status), which is minor since no output schema exists to imply it.

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 coverage is 100% and the single id parameter is already documented with an example format in the schema. The description adds no syntax or constraint beyond what the schema provides, so the baseline 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?

States a specific verb pair (refund/void) and resource (purchased shipping label), which is clearly distinct from buy/create/get siblings. An agent can route here without opening the schema.

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?

Identifies the triggering context (a purchased label that needs reversing) and notes that success is conditional on carrier and label age. It doesn't name an explicit alternative or state when not to use it, but the operation is unambiguous within the sibling set.

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