Create Purchase Order

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

There are no annotations, so the description carries the full burden. It only states the action without disclosing potential side effects like charging, order status implications, or whether it is a one-time or recurring purchase. For a billing tool, this is a significant transparency gap.

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 a single, concise sentence that directly states the purpose. It is appropriately front-loaded and contains no filler, earning a high score for efficiency.

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 no output schema and no annotations, the description leaves out critical context: what the response contains (e.g., order ID, status, payment link), potential errors, and dependencies on other billing tools. For a transaction-like operation, this is incomplete.

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% for both parameters ('items' and 'payment_method_id'), so the baseline is 3. The description adds no extra meaning beyond the schema, such as how to obtain valid item IDs or if there are constraints on cart contents.

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 uses a specific verb ('Create') and a clear resource ('purchase order for Hostinger services'). It distinguishes from sibling billing tools like billing_renew_subscription and billing_get_payment_methods, which handle renewals or retrieval.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention prerequisites such as needing item IDs from billing_get_catalog or payment methods from billing_get_payment_methods, nor does it exclude cases like renewals.

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