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

Annotations already indicate a non-read-only, idempotent, non-destructive operation. The description adds the specific behavioral effect: clearing the opt-out flag rather than performing a broader customer update or deletion. This is useful context beyond the structured annotations.

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 actual guidance is a single, front-loaded sentence that efficiently states the action and consequence. The repeated title line 'Resubscribe Customer' is redundant with the tool name and adds no value, slightly reducing conciseness.

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?

For a simple, single-parameter, idempotent operation with an output schema and comprehensive annotations, the description covers everything an agent needs to know: what state is changed and what the effect is. No critical context 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?

There is only one parameter, and the schema already documents it fully as the unique numeric customer identifier with 100% coverage. The description does not add additional parameter-level meaning, so the baseline score of 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 uses a specific verb ('Clear') and names the exact resource and state being affected ('message opt-out state'), plus the intended outcome ('outreach can resume'). This clearly distinguishes it from sibling tools like unsubscribeCustomer and archiveCustomer.

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 when to use the tool: when a customer's message opt-out state should be cleared so outreach can resume. However, it does not explicitly state when not to use it or mention related alternatives such as unsubscribeCustomer, leaving the selection guidance to inference.

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