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

With no annotations provided, the description carries the behavioral disclosure burden. It explicitly states that it removes never-delivered bounced contacts and preserves those with a prior successful delivery. It also explains the dry-run behavior: 'Sin aplicar:true solo devuelve el recuento, no cambia nada.' This is strong transparency for a mutation-capable tool, although it omits irreversibility details.

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 compact and information-dense: it states what is affected, what is protected, and the dry-run safety behavior in three short sentences. Every sentence contributes crucial context about how the tool behaves.

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?

Despite having no annotations and no output schema, the description is enough for correct invocation: it defines eligibility, the non-destructive preview mode, and required opt-in for actual suppression. Since the params in schema are fully documented, nothing necessary for safe selection and invocation 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?

The input schema covers 100% of the parameters and already describes both `aplicar` and `list_id` well. The description reinforces the key safety semantics of `aplicar` but adds no significant meaning beyond the schema. Therefore 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 opens with a specific verb and resource: 'Saca de circulación a los contactos que rebotaron y NUNCA recibieron ningún correo'. It clearly defines the tool as a hard-bounce cleanup operation and explicitly distinguishes it from simpler subscriber-management actions by describing which contacts are kept.

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 for when to use the tool: to remove dead addresses that never received any email and harm reputation. It also states a clear limit in scope: not to remove contacts that once received mail, whose bounce is transient. It does not name alternative sibling tools, but the selection logic is explicit.

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