WhatsApp MCP Server

send_template_message

Send personalized WhatsApp Business messages using approved templates with dynamic content to recipients, enabling automated communication through the WhatsApp Business API.

Instructions

Send a template message with dynamic parameters via WhatsApp Business API

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "to": "<to>",
      "template_name": "<template_name>"
    },
    "name": "send_template_message"
  }
}

Input Schema

Name	Required	Description	Default
`to`	Yes	Recipient phone number with country code
`template_name`	Yes	Name of the approved template
`parameters`	No	List of template parameters
`language`	No	Template language code	en
`phone_number_id`	No	WhatsApp Business phone number ID (optional, uses env var if not provided)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jan 12, 2026

TDQS

B3.4/5.0

Behavior2/5

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

No annotations are provided, so the description carries full burden. It mentions sending via WhatsApp Business API but lacks critical behavioral details: whether this is a mutation (likely yes, but not stated), rate limits, authentication needs, error handling, or what happens on success/failure. This is inadequate for a tool with potential side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence with zero waste. It is front-loaded with the core purpose and includes key details (dynamic parameters, WhatsApp Business API) without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no annotations, no output schema, and a mutation-like tool (sending messages), the description is incomplete. It lacks information on behavioral traits, return values, error conditions, and usage context relative to siblings. This leaves significant gaps for an AI agent to operate effectively.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema fully documents all parameters. The description adds minimal value beyond the schema by mentioning 'dynamic parameters' and 'via WhatsApp Business API', but does not elaborate on parameter usage, constraints, or examples. Baseline 3 is appropriate as the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('send'), resource ('template message'), and mechanism ('via WhatsApp Business API'), with dynamic parameters highlighted. It distinguishes from siblings like send_text_message or send_image_message by specifying template-based messaging.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for template-based WhatsApp messaging but does not explicitly state when to use this tool versus alternatives like send_text_message or send_button_message. No guidance on prerequisites (e.g., approved templates) or exclusions is provided.

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

Deploy Server