patchResource · SCIM MCP Server MCP: Risk & Policy

WHAT IT DOES

What patchResource does on SCIM MCP Server

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

WHY IT NEEDS A POLICY

Why patchResource needs a policy

PATCH operations are reversible modifications that do not destroy data. This tool creates or modifies data (changing resource state, adding/removing group memberships) but permits undo through subsequent PATCH or other update operations. While it modifies critical identity/access control data (group memberships), it remains in Write category as the changes are not permanent/irreversible.

From the tool's definition Tool description states 'Modify an existing SCIM resource (PATCH)' and explicitly mentions modifying group assignments for users. PATCH is a partial update operation that reversibly modifies resource attributes without deleting data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

patchResource Rate-limited

patchResource 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": {
    "patchResource": {
      "limits": [
        {
          "counter": "patchresource_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 SCIM MCP Server, so you can run agents against it safely.

FAQ

Questions about patchResource

What does the patchResource tool do? +

Modify an existing SCIM resource (PATCH). For assigning and removing groups from an user, PATCH the Group object and use. It is categorised as a Write tool in the SCIM 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 patchResource? +

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

What risk level is patchResource? +

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

Can I rate-limit patchResource? +

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

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

patchResource is provided by the SCIM MCP Server MCP server (limosa-io/mcp-scim). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.