apply_credit_note

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It states the action (apply credit) but does not detail side effects, reversibility, permission requirements, or what happens to the invoice status. For a mutation tool, this is insufficient 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 two concise sentences with no wasted words. It front-loads the action and includes the critical constraint, making it efficient for quick assessment.

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?

Given the simple tool with 3 parameters and no annotations, the description provides the essential purpose and a constraint. However, it lacks details about post-application state (e.g., invoice status change, partial vs full apply) and does not explain the return behavior (no output schema). It is minimally adequate but could be more complete.

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%, so the schema already documents all three parameters. The description does not add parameter-specific details beyond the schema; the only added context is the client-matching constraint, which is not parameter-level. Baseline 3 is appropriate.

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 states the action ('apply a credit note against an open invoice to reduce the amount owed') and identifies both resources (credit note, invoice) with a specific constraint (same client). This distinguishes it from sibling tools like 'apply_supplier_credit' and 'create_credit_note'.

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 provides a clear constraint ('must belong to the same client'), which helps the agent know when the tool is valid. However, it does not explicitly state when to use this tool over alternatives or mention when not to use it.

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