Send a drafted WhatsApp message

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

Annotations already declare not read-only, not idempotent, open-world, and non-destructive. The description goes beyond them by disclosing the draft-consumption side effect and the draft expiry/error path, which explains why the operation is non-idempotent and what a caller must do on failure. It stops short of describing the success response (e.g., resulting message id/status), which is the one remaining behavioral gap.

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?

Front-loads the core action and the 'only call that reaches WhatsApp' distinction, then adds the consumption and expiry facts. Four short sentences, each carrying distinct information, with no filler.

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 two-parameter mutation tool with no output schema, the description covers purpose, routing, side effects, and the error-recovery path, which is enough for correct invocation. It could optionally state what the caller receives on success, but nothing essential 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%, so both draft_id and account_id are already documented in the schema, including the account_id resolution fallback logic. The description repeats that draft_id originates from a send_* tool but adds no format, constraint, or usage detail 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 (send/confirm) and resource (draft from send_* tools), and explicitly bounds the scope with 'the only call that reaches WhatsApp'. An agent can immediately tell it apart from send_message, send_media, and the other drafting siblings.

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 routes the agent: drafts come from send_message/send_media/send_poll/send_location/forward_message, and this is the single call that actually delivers. It also gives a recovery rule for the missing/expired draft case (draft again and re-show the preview). Nothing is left to inference.

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