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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true. The description adds meaningful value beyond that by specifying exactly what is destroyed ('scheduled outreach' / unsent messages) and what is left untouched (archiving, subscription state), which bounds the blast radius an agent should expect.

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?

Short and front-loaded, with the scope-limiting clause carrying the important information. The only waste is the first line restating the title verbatim, which is already provided in the title field.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. The description supplies the scoping constraint needed to invoke it correctly; only a pointer to the archive/unsubscribe alternatives is missing.

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%, with the single 'id' parameter fully documented as the customer's numeric identifier, so the schema does the heavy lifting. The description only implies the id refers to 'this customer' and adds no syntax or format detail beyond the schema. 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 (cancel customer unsent messages) and clarifies scope with 'Clear scheduled outreach for this customer.' It explicitly excludes archiving and subscription-state changes, which helps distinguish it from siblings like archiveCustomer and unsubscribeCustomer, though it names no sibling directly.

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 clause 'without archiving or changing subscription state' gives clear context for when this tool is the right choice versus the neighboring archive/unsubscribe tools. It stops short of explicitly naming those alternatives or stating prerequisites, so it is clear context rather than full when/when-not guidance.

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