cancel_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 of behavioral disclosure. 'Cancel a subscription' implies a destructive mutation, but the description doesn't specify whether this is reversible, what permissions are required, whether it triggers notifications or refunds, or what happens to associated data. For a mutation tool with zero annotation coverage, this leaves critical behavioral aspects undocumented.

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 extremely concise at just three words, with zero wasted language. It's front-loaded with the core action and resource, making it easy to parse quickly. Every word earns its place by directly conveying the tool's purpose without unnecessary elaboration.

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?

Given that this is a mutation tool with no annotations, no output schema, and a description that only states the basic purpose, the description is incomplete. It doesn't address behavioral aspects like side effects, permissions, or return values, nor does it provide usage context relative to sibling tools. For a tool that performs a potentially significant action like subscription cancellation, more contextual information is needed.

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%, so the schema already documents both parameters ('subscriber_code' and 'send_email') with their types and descriptions. The description adds no additional meaning about these parameters beyond what the schema provides, such as explaining what a subscriber code represents or the implications of sending email. Baseline 3 is appropriate when the 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 'Cancel a subscription' clearly states the action (cancel) and resource (subscription), but it's quite basic and doesn't differentiate from potential sibling tools. It doesn't specify what type of subscription or cancellation process is involved, making it somewhat vague despite having a clear verb+resource structure.

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 no guidance on when to use this tool versus alternatives. With sibling tools like 'list_subscriptions' and 'refund_purchase' available, there's no indication of whether this tool should be used for active vs. pending subscriptions, or how it relates to refund operations. No context about prerequisites or exclusions is mentioned.

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