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

Annotations already indicate this is not read-only, idempotent, and not destructive. The description adds valuable behavior beyond annotations by explaining the consequence of suppression: addresses 'must never be emailed again' and are 'skipped by every campaign automatically.' This makes the side-effect profile clearer without contradicting the 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?

Two short sentences, front-loaded with the action, and no wasted wording. The most important behavior (global campaign skip) is included without elaboration.

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?

The description plus full schema coverage together account for the action enum (stats/list/add) and all parameters. The description omits explicit mention of the 'list' action, though the title and schema cover it. For a moderate-complexity tool with no output schema and strong annotations, this is reasonably complete.

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%, so all four parameters are already documented with types, defaults, and purposes. The rubric assigns a baseline of 3 in this case; the description adds only light semantic color ('never emailed again') but does not materially enrich parameter understanding 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 specific verbs and a resource: 'Read suppression stats or add addresses' targeting the 'Bounce shield suppression list'. It also clarifies the functional scope ('must never be emailed again' and 'skipped by every campaign automatically'), which differentiates it from sibling tools like verify_email or check_deliverability.

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 gives clear context: use this tool to inspect suppression stats or ban addresses from future emails. It does not explicitly name alternatives or state when not to use it, but the operation is unique among the long sibling list, so the intended usage is reasonably inferable.

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