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

With no annotations, the description carries the full burden and delivers: it discloses side effects ('No reanuda flujos viejos ni envía la bienvenida'), error semantics (409 codes, domain_sugerido payload), and required preconditions. This is rich behavioral context beyond a plain mutation statement.

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?

Purpose is front-loaded in the first clause, followed by conditions, error behavior, and the sibling alternative. It is dense and slightly long, but each clause (bounce type, domain validity, 409 payload, side effects, alternative) earns its place.

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 single-parameter reactivation tool with no output schema or annotations, the description supplies preconditions, error responses, and side effects. Nothing an agent needs to call it correctly 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 coverage is 100% and the single 'email' parameter is already documented as accepting an email or id. The description's note about correcting the address (gmail.co, hormail.com) touches on input validity but does not add syntax or format meaning beyond the schema. Baseline 3 applies.

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 and resource ('Devuelve a tus envíos a un contacto que salió por un rebote TEMPORAL') and immediately scopes it to temporary bounces, distinguishing it from generic subscriber updates. An agent can tell what it does and what it does not do.

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?

Explicitly lists preconditions (temporal bounce only, domain not blocked/misspelled, no unsubscribe/spam), the failure mode (409 with reason), and names the alternative it replaces ('Úsalo en vez de update_subscriber con status "active"'). When/when-not/alternative are all present.

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