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

Annotations already indicate destructiveHint=true and readOnlyHint=false, signaling mutation. The description adds little beyond that: it states 'Update subscription cancellation state' but does not disclose consequences of cancelSubscription (e.g., whether cancellation is permanent, reversible). No additional behavioral traits are revealed.

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, front-loaded sentence (22 words) with no wasted words. It is appropriately sized for the tool's purpose.

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 4 parameters (including a nested array), a destructiveHint, and no output schema, the description is too sparse. It omits the effect of cancelSubscription, the structure of cancellationReasons, and any success/error indications. The tool is a mutation with significant side effects, requiring richer context.

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?

With 0% schema description coverage, the description only explains the confirm parameter ('Requires confirm set to UPDATE_SUBSCRIPTION'). It provides no extra meaning for orderObjectId, cancelSubscription (e.g., what true/false does), or cancellationReasons (structure/usage). This partially compensates but is insufficient.

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 clearly states the verb 'update' and the resource 'subscription cancellation state for a custom-domain order'. It is specific and distinguishes the tool's action, but does not differentiate from sibling tools like set_business_custom_domain_subscription_cancellation or set_community_custom_domain_subscription_cancellation.

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 that the tool should be used when updating cancellation state for a custom-domain order and requires the confirm parameter. However, it does not provide guidance on when not to use it, nor does it explain how to choose between this generic version and the business/community-specific siblings.

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