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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false. The description adds meaningful context about the cancel-unsent-messages behavior, which is not captured in the annotations. However, it does not explain whether archiving is reversible or how idempotency manifests.

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 short and front-loaded with the action, but it redundantly repeats the tool name 'Archive Customer' as the first sentence. The second sentence adds the side effect. Overall it is concise with minimal waste.

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?

With only one parameter and an output schema present, the description covers the main effect and side effect. It does not specify what 'archive' means for customer status or whether the cancel operation applies to all unsent messages, but these are minor gaps given the tool's simplicity.

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 single parameter 'id' is clearly described as a unique numeric identifier. The description adds no additional parameter semantics beyond what the schema provides, so 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?

The description clearly states the primary action ('Archive a customer') and adds a specific side effect ('cancel any unsent outreach messages'). This distinguishes it from related siblings like deleteCustomer (destructive) and unarchiveCustomer (reverse operation), making the purpose unambiguous.

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 via the side effect (archiving when you want to cancel unsent outreach) but does not explicitly state when to use this tool over alternatives like deleteCustomer or unarchiveCustomer. There is no mention of conditions or exclusions.

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