Meta Cloud API MCP Server

update_flow_json

Update a WhatsApp Flow's JSON definition by providing the flow ID and new JSON content, replacing the existing configuration.

Instructions

Upload or update the Flow JSON definition for a WhatsApp Flow. Accepts JSON as a string or object.

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": {
      "flow_id": "<flow_id>",
      "flow_json": "<flow_json>"
    },
    "name": "update_flow_json"
  }
}

Input Schema

Name	Required	Description	Default
`flow_id`	Yes	The Flow ID to update
`flow_json`	Yes	Flow JSON definition (string or object)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 9, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full burden of behavioral disclosure. It does not explain whether the update replaces the entire definition, effects on existing data, validation behavior, required permissions, or response semantics, which are critical for a mutation tool.

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?

Two concise sentences: the first states the purpose, the second adds input flexibility. No fluff, front-loaded, and every word earns its place.

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?

For a simple upload/update tool with two parameters, the description is minimal but lacks crucial context: no response format, no error or validation notes, no relationship to other flow lifecycle tools. Given no annotations or output schema, the description should fill more gaps.

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 coverage is 100%, so the baseline is 3. The description's statement about accepting JSON as string or object is redundant with the schema's anyOf definition and adds no new semantic meaning beyond what's already structured.

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 tool uploads or updates the Flow JSON definition for a WhatsApp Flow, identifying a specific resource and action. It distinguishes from siblings like update_flow_metadata by focusing on the JSON definition, though 'Upload or update' is slightly ambiguous.

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?

No guidance is provided on when to use this tool versus alternatives such as create_flow, update_flow_metadata, or publish_flow. The description gives no context for selection among the many related flow tools.

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