create_subscription

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

No annotations are provided, so the description carries the full burden. It only states 'Create', implying a write operation, but lacks details on idempotency, duplicate handling, success response, or any prerequisites (e.g., authentication). This is insufficient for understanding the tool's behavior.

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 sentence, making it concise, but it is too brief to be truly helpful. It sacrifices necessary detail for brevity, such as behavioral hints or usage context.

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 10 parameters and no output schema, the description fails to explain return values, error handling, or preconditions. For example, it does not state whether the tool requires authentication or how to handle validation failures. This is inadequate for the complexity of the tool.

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 covers all 10 parameters with descriptions (100% coverage), so the schema already provides parameter semantics. The description adds no additional meaning beyond the schema, earning a baseline of 3.

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 'Create a new subscription' clearly states the verb and resource, making the primary purpose obvious. However, it does not differentiate from sibling tools like 'backfill_subscription' or 'update_subscription', which could cause confusion.

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?

There is no guidance on when to use this tool versus alternatives. For instance, it does not explain when to use 'create_subscription' instead of 'backfill_subscription' or 'mark_subscription_paid', leaving the agent to infer usage context.

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