Send WhatsApp Document

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

Annotations already indicate this is a non-read-only, non-idempotent operation. The description adds valuable context: the requirement for a public URL, optional filename/caption, and a return value of 'Message ID and delivery status.' It does not contradict annotations and provides behavioral expectations beyond the safety profile.

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 concise and well-structured. The opening sentence states the core purpose, followed by a clear Args list and Returns line. No redundant text or unnecessary elaboration; every sentence contributes useful information.

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?

With no output schema, the description appropriately includes a Returns line ('Message ID and delivery status'). It covers the essential aspects: purpose, parameters, and outcome. It lacks potential error scenarios or response format details, but for a straightforward send operation with good annotations, this is sufficient. A small gap is the absence of clarification on how errors (like invalid URL) are reported, preventing a 5.

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 100%, so the schema already describes all parameters. The description repeats the args list with similar wording (e.g., 'Public URL' vs schema's 'Public URL of the document to send') and does not add new semantic details beyond what the schema provides. The baseline of 3 applies because the schema carries the burden.

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 clearly states the tool's action: 'Send a document (PDF, DOCX, etc.) to a WhatsApp user via a public URL.' It uses a specific verb ('send'), resource ('document'), and context ('via a public URL'), and it is distinct from sibling tools like whatsapp_send_text or whatsapp_send_image by specifying document types.

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?

The description implies the usage context (when you need to send a document), but it does not explicitly contrast with alternatives or state when not to use this tool. The sibling tools are not referenced, so an agent must infer from the name. This meets the 'implied usage' level but lacks explicit when/when-not guidance.

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