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

Annotations already flag destructiveHint=true and idempotentHint=true, and the description adds the concrete meaning behind both: this is a mass send that cannot be undone, and already-sent or in-flight campaigns will not be dispatched again. It also supplies a required confirmation guardrail (name, template, recipient count, explicit user consent) that no annotation conveys.

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?

Three tight sentences, front-loaded with the action, then the risk, then the mandatory confirmation step and the idempotency rule. No filler or repetition.

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 an irreversible mass-send tool with no output schema, the description covers the critical gaps: irreversibility, confirmation protocol, and non-resend behavior. Minor omissions remain, such as how the agent obtains campaign_id and what the response reports after dispatch.

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 50%: brand_id is documented in the schema, but campaign_id has no schema description. The description refers to a 'prepared campaign' and its name/template/recipients but never explains that campaign_id identifies it or where to obtain it (presumably whatsapp_create_campaign). Baseline 3 for partial coverage with only marginal added meaning.

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: sending an already-prepared campaign to its full list, immediately ('Envía ahora'). The phrase 'campaña preparada' implicitly separates it from whatsapp_create_campaign and 'ahora' from whatsapp_schedule_message, but neither sibling is named outright, so differentiation relies on inference.

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?

It gives a clear usage protocol: before sending, tell the user the campaign name, template and recipient count, and wait for an explicit yes. It also states the exclusion case (a campaign already sent or in progress is not re-sent). It stops short of naming the alternative tools to use when the user wants to schedule rather than send now.

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