Renew Subscription

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly states that creating the order will use the default payment method if none is supplied, which is a crucial side effect for an agent to know. It doesn't mention charge processing or other side effects, but it covers the most important behavioral nuance.

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 consists of two sentences, both essential: the first states the core action, the second adds the fallback behavior. No redundancy or filler.

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 tool with no output schema, the description provides all necessary information: what it does, on what entity, and the key default behavior. It is complete enough for an agent to select and invoke correctly.

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 schema already documents both parameters with descriptions, and the description reinforces the optional nature of payment_method_id by noting the default behavior. This adds practical guidance beyond the schema, though the schema is already sufficient.

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 specific action ('Create a renewal order') and the target resource ('an existing subscription'), distinguishing it from sibling tools like billing_enable_auto_renewal or billing_create_order. The verb and resource are unambiguous.

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 clear context for when to use the tool (renewing an existing subscription), but it doesn't explicitly exclude alternatives like auto-renewal. The mention of default payment method implies the expected scenario of manual renewal.

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