create_context · Fast MCP: Risk & Policy

WHAT IT DOES

What create_context does on FastMCP

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

WHY IT NEEDS A POLICY

Why create_context needs a policy

The tool creates new contexts within the system. While the description is empty (lowering confidence), the name and context of sibling tools (delete_context, update_context) indicate reversible data modification. This is a Write operation because contexts are created but can be deleted or modified later.

From the tool's definition Tool name 'create_context' indicates creation of data. Sibling tools show this server manages contexts (get_context, update_context, delete_context, list_contexts), confirming data structure manipulation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_context Rate-limited

create_context 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_context": {
      "limits": [
        {
          "counter": "create_context_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 FastMCP, so you can run agents against it safely.

FAQ

Questions about create_context

What does the create_context tool do? +

create_context. It is categorised as a Write tool in the FastMCP 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_context? +

Register the Fast MCP server in PolicyLayer and add a rule for create_context: 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 FastMCP. Nothing to install.

What risk level is create_context? +

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

Can I rate-limit create_context? +

Yes. Add a rate_limit block to the create_context 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_context completely? +

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

create_context is provided by the Fast MCP server (ryuichi1208/datadog-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.