Credit invoice amount

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

Annotations already mark destructiveHint=true; description adds context by stating it 'moves money / changes billing records', providing specific impact beyond the annotation. 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?

Three concise sentences, each carrying meaningful information: purpose, full-credit usage guidance, and a destructive warning. No wasted words, front-loaded with the core action.

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 5 parameters, no output schema, and annotations available, the description covers key decision points (full credit, refund source, destructive side effects). It does not mention return values, but for a mutation tool with schema descriptions, this is acceptable and the description is sufficient.

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 descriptions cover 100% of parameters and already explain 'amount' as 'omit = remaining' and 'refund_source' as '0 original source, 1 wallet only'. The description only repeats this information, adding no new semantics 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?

Description clearly states 'Issue a credit note against an invoice', a specific verb and resource. It distinguishes from sibling tools like refund_invoice by specifying 'credit note' rather than refund, and clarifies full-credit behavior.

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?

Gives clear context on usage: 'Omit amount to credit the full remaining amount, or set full_credit=true' and explains refund_source options. However, it does not explicitly mention when not to use it or mention alternatives like refund_invoice, so it lacks exclusions.

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