add_column · SharePoint MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_column does on SharePoint MCP Server

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

WHY IT NEEDS A POLICY

Why add_column needs a policy

The add_column tool creates a new column in SharePoint lists/libraries, which modifies the schema structure. This is a Write operation because it creates and modifies data structures reversibly—columns can be deleted or modified later (as evidenced by the sibling delete_column tool). It is not Destructive because the operation is reversible.

From the tool's definition Tool description states it will 'Add a new column to an existing list or library' with automatic inclusion in the default view. This is a reversible data schema modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_column Rate-limited

add_column 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": {
    "add_column": {
      "limits": [
        {
          "counter": "add_column_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 SharePoint MCP Server, so you can run agents against it safely.

FAQ

Questions about add_column

What does the add_column tool do? +

Add a new column to an existing list or library. The column is automatically added to the default view unless addToDefaultView is false. It is categorised as a Write tool in the SharePoint 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 add_column? +

Register the SharePoint MCP Server MCP server in PolicyLayer and add a rule for add_column: 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 SharePoint MCP Server. Nothing to install.

What risk level is add_column? +

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

Can I rate-limit add_column? +

Yes. Add a rate_limit block to the add_column 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 add_column completely? +

Set action: deny in the PolicyLayer policy for add_column. 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 add_column? +

add_column is provided by the SharePoint MCP Server MCP server (lukassevcik/sharepoint-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.