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

The description says 'Calling this changes nothing: it returns a preview of what would change and a confirmation link,' which describes read-only behavior. This directly contradicts the annotation readOnlyHint=false, making the definition internally inconsistent about side effects.

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 front-loaded and compact, with the purpose and preview behavior stated early. The sentence about money units is irrelevant to this schema's parameters, so it is minor wasted space but not severe.

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?

There is no output schema, so the description appropriately explains what the call returns: a preview and a confirmation link. Combined with the fully documented input schema and the clarification that only the merchant can confirm the change, an agent has enough context to invoke the tool correctly.

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%, and the schema itself gives detailed semantics for all six parameters. The description adds only 'Money is integer minor units (cents),' which does not apply to any actual parameter here, so it provides no useful parameter meaning beyond the schema.

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 and resource: 'Set tipping and abandoned basket emails.' This clearly distinguishes the tool from sibling settings tools such as settings_checkout, settings_notifications, and settings_identity by scoping it to checkout extras.

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 purpose implies when to use the tool, and the description notes that only the merchant can finalize the action via a confirmation link. However, it does not explicitly state when to use this tool versus alternatives like settings_checkout or settings_notifications, nor does it define exclusions.

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