@nightsquawktech/gohighlevel-mcp-server

Create GoHighLevel Custom Field V2

ghl_create_custom_field_v2

Create a custom field in GoHighLevel by specifying name, object key, and data type. Optionally define options, placeholder, and other settings via API.

Instructions

Create a Custom Fields V2 field with POST /custom-fields/. Write operation: do not run against live data without explicit approval.

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": {
      "name": "<name>",
      "objectKey": "<objectKey>",
      "dataType": "<dataType>"
    },
    "name": "ghl_create_custom_field_v2"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes	Custom field name.
`extra`	No	Optional additional GoHighLevel fields to pass through when the API supports fields not modeled by this tool.
`options`	No
`dataType`	Yes	GoHighLevel custom field type.
`parentId`	No
`objectKey`	Yes	Object key, for example custom_objects.pet or business.
`locationId`	No	Optional explicit location ID. Defaults to GHL_LOCATION_ID.
`description`	No
`placeholder`	No
`showInForms`	No
`maxFileLimit`	No
`acceptedFormats`	No
`response_format`	No	Output format: markdown for human-readable summaries, json for structured output.	markdown
`allowCustomOption`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 29, 2026

TDQS

A3.7/5.0

Behavior3/5

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

The annotations indicate readOnlyHint=false, meaning it's a write operation, and the description labels it as such. The warning about live data adds behavioral context. However, the description does not disclose idempotency (false), potential side effects, or error behavior. The openWorldHint=true is not addressed.

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 extremely concise: two sentences covering the action, endpoint, and a usage warning. No redundancy or unnecessary information. It is front-loaded with the key purpose.

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 14 parameters, 3 required, no output schema, and complex options like nested objects for 'options', the description is too sparse. It does not explain the return format, the relationship between parameters (e.g., parentId vs objectKey), or how 'extra' works with openWorldHint. The agent lacks sufficient context to use the tool correctly.

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

Parameters2/5

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

With only 43% schema description coverage, the description should compensate for undocumented parameters, but it does not. It adds no parameter-level explanations beyond the schema. For example, 'options', 'parentId', 'placeholder' are not explained in the description, leaving gaps for the agent.

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 specifies the action (create a Custom Fields V2 field) and the API endpoint (POST /custom-fields/). It effectively distinguishes this tool from siblings like ghl_get_custom_field_v2, ghl_update_custom_field_v2, and ghl_delete_custom_field_v2 by explicitly stating the create operation.

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

Usage Guidelines4/5

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

The description provides a clear warning: 'Write operation: do not run against live data without explicit approval.' This guides the agent on when to proceed with caution. However, it does not explicitly differentiate when to use this tool over alternatives like ghl_create_custom_field (V1) or ghl_create_custom_field_folder, nor does it mention prerequisites.

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

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