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

Adds meaningful behavior beyond annotations: cancellation runs to the end of the paid period and the listing remains with its date. Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so this timing/lifecycle detail is the true value-add. It does not specify auth requirements or how to recover a cancelled drive, but covers the key behavioral nuance.

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, zero waste, front-loaded with the verb and resource. The lifecycle note and listing-persistence note each earn their 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?

Complete for a single-parameter mutation tool: it explains scope, timing, and post-cancellation state. With no output schema, it reasonably omits return-shape details since the description says the listing persists, making the resulting state predictable.

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 coverage is 100% and the schema already documents order_id and the leave-out-to-cancel-all semantics. The description repeats this scoping behavior but adds no format, syntax, or sourcing detail beyond what the schema provides; baseline 3 is appropriate.

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?

States a specific verb+resource (cancels the Monthly drive) with clear scope: one product via order_id or all of them. The tool is distinguishable from siblings like drive_stop and switch_monthly without opening any schema.

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 implies usage (leave order_id out to cancel all) but gives no explicit when-to-use context, no prerequisites, and does not name alternative tools like switch_monthly or drive_stop that an agent might consider.

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