trigger_refund

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

With no annotations, the description carries the full behavioral burden; it does disclose the key side effect (the refundable balance is reduced) and the validation gates that cause rejection. It omits idempotency/retry behavior, required permissions, what happens for an inactive or unknown customer, and whether the reduction is immediate.

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 tight sentences, front-loaded with purpose and behavior, followed by the validation rules. No filler, and the most decision-relevant constraint (cannot exceed refundable balance) is included rather than left implicit.

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?

An output schema exists, so return values need not be described, and the amount/reason boundaries are covered. Still missing for a 3-required-param money-movement tool: how to obtain or validate `customer_id`, failure modes for inactive customers, and idempotency guarantees.

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 0%, so the description must compensate; it adds genuinely new semantics for `amount` (at most 2 decimal places, must not exceed the refundable balance) and `reason` (length measured after trimming). However, `customer_id` is only implied via 'active customer' — the CUST-##### format and lookup requirement are never explained.

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?

Opens with a specific verb + resource + effect: issuing a refund and reducing the refundable balance. This is clearly a mutation distinct from the read-only sibling get_customer_record, though the description never names that sibling to make the contrast explicit.

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?

There is no explicit when-to-use or when-not-to-use guidance, and the only alternative tool (get_customer_record) is not mentioned, even though an agent likely needs it first to verify balance and active status. The precondition 'active customer' is the only usage hint, and it is stated as a constraint rather than as a workflow step.

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