Send Whatsapp

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

With no annotations, the description must carry behavioral disclosure. It usefully states that a browser window opens and first run requires a QR scan, but it does not describe delivery behavior, authentication persistence, rate limits, or failure modes for an external send operation.

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 a single front-loaded sentence with zero wasted text. The parenthetical setup caveat is operationally useful and does not obscure the main action.

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?

An output schema exists, so return values need not be explained. The description covers the main action plus browser/QR setup, but for a send tool with no annotations it leaves important context about immediacy, authentication state, and delivery outcomes unstated.

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 67%, with phone_number and default_region well documented in the schema. The description adds no parameter syntax or constraints beyond what the schema provides, and the message parameter remains undescribed in both places.

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 a specific verb and resource: send one WhatsApp message via WhatsApp Web. It is distinguishable from send_email by channel, though it does not explicitly contrast with sibling tools such as preview_message.

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?

Usage is implied by 'Send one WhatsApp message,' and the first-run QR note helps with setup context. However, it does not say when to choose this over send_email or preview_message, nor does it give exclusions or prerequisites beyond the QR scan.

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