WhatsApp MCP Server

send_image_message

Send images via WhatsApp Business API by providing recipient phone number and image URL. Add optional captions to share visual content in business communications.

Instructions

Send an image message 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>",
      "image_url": "<image_url>"
    },
    "name": "send_image_message"
  }
}

Input Schema

Name	Required	Description
`to`	Yes	Recipient phone number with country code
`image_url`	Yes	Public URL of the image to send
`caption`	No	Optional caption for the image
`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

C2.9/5.0

Behavior2/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('Send') but doesn't cover critical aspects like authentication needs, rate limits, error handling, or what happens on success/failure. This is a significant gap for a mutation tool in a messaging API context.

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 that directly states the tool's purpose without any fluff or redundancy. It's appropriately sized and front-loaded, making it easy to parse quickly.

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 the complexity of a messaging API tool with no annotations and no output schema, the description is incomplete. It doesn't explain return values, error cases, or behavioral traits, leaving the agent with insufficient context to use the tool effectively beyond basic parameter passing.

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?

The input schema has 100% description coverage, so parameters are well-documented in the schema itself. The description adds no additional semantic context beyond what the schema provides (e.g., format details for 'to' or 'image_url'), resulting in a baseline score of 3 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.

Purpose4/5

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

The description clearly states the action ('Send') and resource ('image message via WhatsApp Business API'), making the purpose immediately understandable. However, it doesn't differentiate this tool from its siblings (like send_audio_message, send_video_message) beyond specifying the media type, missing an opportunity to clarify unique aspects.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus alternatives (e.g., send_text_message for text, send_template_message for templates). It lacks context about scenarios where sending an image is appropriate, prerequisites, or any exclusions, leaving usage decisions ambiguous.

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

Deploy Server