Send WhatsApp message

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

With no annotations, the description carries the full burden. It discloses the media_url requirement but does not mention side effects, error conditions, required connectivity state, or what happens if the device is not connected. The send operation is implied but its execution details are opaque.

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 two sentences, front-loaded with the purpose. The second sentence provides a critical constraint without wasted words, making it appropriately concise.

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?

Given 9 parameters, no annotations, and no output schema, the description is too sparse. It omits details about group messaging, optional fields like caption/filename/mimetype, defaults for type, device_id selection, and expected response behavior, leaving significant gaps for the agent.

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 the schema documents all 9 parameters. The description adds minimal extra information by restating the public https media requirement, which already appears in the schema. It does not explain parameter interactions like ptt for audio or group JID usage.

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 clear verb ('Send') and resource ('WhatsApp text or media message'), and specifies a prerequisite ('from a connected LoginWA device'). It is distinct from sibling campaign tools by focusing on one-off direct messages, though it does not explicitly contrast with send_campaign.

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?

No guidance is given for when to use this tool versus alternatives like send_campaign. The only usage-related information is a requirement that media types need a public https media_url and the tool uses a connected device, which are prerequisites rather than selection criteria.

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