Update subscription item

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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description, however, adds nothing about the mutation's effects (quantity changes, proration, immediate invoicing) or what the `confirm` flag gates. It merely says attributes are updated.

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?

A single short, front-loaded sentence with no filler, which is fine structurally. However, the brevity is achieved through under-specification rather than efficiency, so it does not fully earn its place.

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 destructive, non-idempotent mutation with a nested object body, 8 parameters, and no output schema, the description is far too thin. It never mentions the payload structure, the confirm requirement, or what the update returns, leaving significant gaps for an agent.

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?

With 8 parameters and 63% schema description coverage, several parameters (quantity, disable_prorations, invoice_immediately, confirm) have no schema descriptions, and the description does not compensate. "Provided attributes" is the only hint and does not explain the payload vs. flat-parameter vs. payload_file mutual exclusion documented only in the schema.

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 essentially restates the title ("Update subscription item" -> "Updates the subscription with the given ID"). Worse, it names the resource as "subscription" rather than "subscription item," which blurs the distinction from the sibling update_subscription. There is no differentiation from any sibling tool.

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 when-to-use guidance, no prerequisites, and no routing to alternatives such as update_subscription or get_subscription_item. The critical distinction between updating a subscription versus a subscription item is left entirely to inference.

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