Resume a subscription

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

Annotations already signal readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the description does not need to restate those. It adds useful context: billing restarts and cancelled subscriptions cannot be revived. However, it does not mention potential side effects like proration, payment failures, or whether resuming an already-active subscription is a no-op, though the idempotent hint partially covers that.

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?

Three short sentences, each earning its place: the action, the relationship to a sibling tool, and an important limitation. The primary purpose is front-loaded and there is no fluff.

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 two-parameter tool with complete schema coverage and informative annotations, the description sufficiently covers purpose, usage boundaries, and key behavioral constraints. No critical missing context prevents an agent from selecting or invoking this tool 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 input schema already describes both parameters with 100% coverage, including their sources and defaults. The tool description adds no parameter-level meaning, so the baseline score of 3 is appropriate; schema does the heavy lifting.

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 states a specific verb and resource: 'Resume a paused subscription, restarting billing.' It also differentiates itself from siblings by explicitly naming itself as the counterpart to pause_subscription and clarifying it is not for cancelled subscriptions.

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?

It clearly says when to use the tool (for paused subscriptions) and when not to use it (for cancelled subscriptions, which cannot be revived). It also names the related sibling pause_subscription, providing an explicit alternative and context.

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