create_field

THE RISK

Medium Risk

Why create_field needs a policy

This tool modifies the database schema by adding a new field/column to a table. Schema modifications are write operations because they change the structure of data storage, even though they don't directly create data records. The operation is reversible (via delete_field sibling tool), placing it in Write rather than Destructive.

From the tool's definition Tool name is 'create_field' and description states 'Create a new field in a table'. This creates new data structure elements (schema modification) that are reversible via delete_field.

Documented attack patterns abuse exactly the kind of access create_field gives an agent:

POLICY

How to control create_field

PolicyLayer is an MCP gateway — it sits between your AI agents and Teable MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for create_field:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_field": {
      "limits": [
        {
          "counter": "create_field_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_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.

Create a free account and register Teable MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Teable MCP Server tools

Destructive delete_field Permanently delete a field from a table (all data in this field will be lost) Destructive delete_record Permanently delete a record (all data will be lost). This operation is irreversible. Destructive delete_table Delete a table (moves to trash, recoverable via restore_table_from_trash) Destructive delete_view Delete a view from a table Destructive permanently_delete_table Permanently and irreversibly delete a table. This cannot be undone. The table must already Write share_view Enable or disable public share link for a view. Returns the share URL when enabled. Write comment_on_record Post a comment on a specific record Write create_record Create a new record in a table

All 29 Teable MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about create_field

What does the create_field tool do? +

Create a new field in a table. It is categorised as a Write tool in the Teable MCP Server 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_field? +

Register the Teable MCP Server MCP server in PolicyLayer and add a rule for create_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 Teable MCP Server. Nothing to install.

What risk level is create_field? +

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

Can I rate-limit create_field? +

Yes. Add a rate_limit block to the create_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_field completely? +

Set action: deny in the PolicyLayer policy for create_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_field? +

create_field is provided by the Teable MCP Server MCP server (ltphat2204/teable-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Teable MCP Server tool call.

Start from Teable MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →