Create External Transaction

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only restates the core action ('create') and adds no information about mutability, idempotency, required authorizations, side effects, uniqueness constraints, or what occurs on success. The parenthetical 'alternative billing' adds some domain context, but no real behavioral transparency.

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 one compact, front-loaded sentence with no filler. Every word contributes meaning, and the parenthetical clarification is valuable without adding bloat.

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 simple create operation with full schema coverage and an output schema, the description is minimally adequate. However, it lacks any guidance on when to use this instead of related external-transaction tools, and it gives no behavioral caveats. The nested transaction object would benefit from at least a phrase clarifying what kind of payload is expected.

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 input schema already provides 100% coverage of all parameters with descriptions for package_name and external_transaction_id. The description adds minimal meaning beyond the schema; 'alternative billing' hints at the transaction's purpose, but it does not clarify the nested transaction object structure or parameter relationships. Baseline 3 is appropriate given the high schema coverage.

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 states a specific verb ('create'), a specific resource ('external transaction'), and adds the clarifying qualifier 'alternative billing' that distinguishes it from regular billing operations. It clearly identifies what the tool does and is easily distinguishable from sibling tools like get_external_transaction and refund_external_transaction.

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 guidance on when to use this tool versus alternatives. It does not mention that get_external_transaction or refund_external_transaction should be used for reading or refunding external transactions, nor does it give any contextual cues about prerequisites or business scenarios for creating an external transaction.

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