Cancel subscription

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 adds only the implicit 'active subscription' precondition and says nothing about whether cancellation is immediate vs. end-of-period, reversibility, or how the confirm flag gates the action.

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 front-loaded sentence with no filler. It is efficiently sized, though its brevity comes at the cost of the behavioral detail scored elsewhere.

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 no output schema, the description omits critical context: what state change occurs, whether it can be undone, and what the confirm parameter actually protects against. The schema covers parameters, but the behavioral picture remains thin.

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%: the schema documents id, account, and confirm with meaningful descriptions (including the 'set true only when the user asked for exactly this action' guard). The description adds no parameter-level detail, so the baseline 3 is correct.

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 (cancels) and resource (subscription) plus a scope qualifier ('active'), so the agent knows exactly what the tool does. It does not distinguish itself from adjacent siblings like update_subscription, but the purpose is unambiguous on its own.

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 versus update_subscription or delete-type siblings, nor any stated prerequisites. The word 'active' hints at a precondition, but the agent must infer it rather than being told.

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