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

Annotations already declare destructiveHint=true, readOnly=false, and idempotent=false. The description adds valuable behavioral context beyond annotations: the charged amount is credited back to the account balance, and the state precondition (`state=queued`) is disclosed. No contradiction with annotations.

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 concise and front-loaded: first line states the action and resource, then the paragraph adds the eligibility condition and financial effect. Every sentence earns its place without redundancy.

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 mutation tool with a provided output schema and annotations covering destructiveness, the description covers the essential operational facts: what is cancelled, when it can be cancelled, and what happens to the charged amount. Nothing needed for correct invocation 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?

Schema description coverage is 100% and the only parameter, `card_id`, is already well documented by the schema with its source (`returned from /order-intl-card`). The description reinforces that it is a queued order ID but does not add significant meaning beyond the schema.

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 ('Cancel') and resource ('queued international card order'), and adds the key qualifier 'non-reloadable' with the state constraint `state=queued`. This clearly distinguishes it from sibling ordering tools like `order_intl_card`, `order_card`, and `order_gift_card`.

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 explicitly states when the tool applies: only for a previously queued order that has not yet been fulfilled by an admin. It gives a clear exclusion ('as long as it has not yet been fulfilled') but does not name an alternative tool or explain what to do if the condition is not met.

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