Apply transaction to invoices

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

Annotations already indicate the operation is not read-only, not idempotent, and not destructive. The description adds useful context about the same-currency requirement and that it consumes an unapplied balance, but it does not disclose side effects on the transaction's remaining balance, failure modes, or whether partial applications are allowed.

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 concise sentences with no filler. The primary action and constraint are front-loaded, and the 'Wraps Transactions.apply' note adds implementation context 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 simple two-parameter operation, the description is mostly adequate, especially with annotations covering the safety profile. However, the absence of an output schema and any mention of return values, error conditions, or behavior when the unapplied balance is insufficient leaves gaps for an agent planning to invoke the tool.

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% and the description does not explain transaction_id or amounts. It only implies their roles ('existing transaction' and 'one or more invoices'), leaving the agent to infer that amounts is an array of invoice_id/amount pairs from the schema structure. This is insufficient compensation for the lack of schema descriptions.

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 clearly identifies the action ('Apply'), the resource (an existing transaction's unapplied balance/client credit), and the target (one or more invoices). The 'same currency' constraint and the concept of existing client credit distinguish it from sibling tools like process_payment or record_manual_payment without requiring schema inspection.

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?

Usage is implied: this tool is for allocating an existing transaction's unapplied balance to invoices. However, there is no explicit guidance on when to choose this over related tools like record_manual_payment or process_payment, nor any exclusion criteria such as 'use only when the transaction is a credit'.

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