create-custom-field · Salesforce MCP: Risk & Policy

WHAT IT DOES

What create-custom-field does on Salesforce MCP

AI agents use create-custom-field to create or update resources in Salesforce MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Salesforce MCP environment.

WHY IT NEEDS A POLICY

Why create-custom-field needs a policy

Creating a custom field in Salesforce is a Write operation as it creates new metadata that persists in the system. While reversible (fields can be deleted), it modifies the underlying data structure and can have widespread side effects on dependent configurations, workflows, validation rules, and integrations.

From the tool's definition Tool name is 'create-custom-field' and description states 'Create a Custom Field'. This creates a new field in Salesforce, which modifies the schema and data structure of Salesforce objects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create-custom-field Rate-limited

create-custom-field stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create-custom-field": {
      "limits": [
        {
          "counter": "create-custom-field_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Salesforce MCP, so you can run agents against it safely.

FAQ

Questions about create-custom-field

What does the create-custom-field tool do? +

Create a Custom Field. It is categorised as a Write tool in the Salesforce MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create-custom-field? +

Register the Salesforce MCP server in PolicyLayer and add a rule for create-custom-field: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Salesforce MCP. Nothing to install.

What risk level is create-custom-field? +

create-custom-field is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create-custom-field? +

Yes. Add a rate_limit block to the create-custom-field rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block create-custom-field completely? +

Set action: deny in the PolicyLayer policy for create-custom-field. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides create-custom-field? +

create-custom-field is provided by the Salesforce MCP server (jpmonette/salesforce-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.