update_function · Theagora MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_function does on Theagora MCP Server

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

WHY IT NEEDS A POLICY

Why update_function needs a policy

This tool creates or modifies data reversibly. While it affects marketplace listings and pricing (which could have financial implications), the core action is updating metadata and configuration parameters of a service listing, not moving money or irreversibly destroying data. The ability to deactivate (set isActive to false) is reversible.

From the tool's definition Tool allows updating function listing properties: name, description, pricing, QoS, and isActive status. Description explicitly states 'Only the owning provider can update a function,' indicating write-level modifications to marketplace data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_function Rate-limited

update_function 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": {
    "update_function": {
      "limits": [
        {
          "counter": "update_function_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 Theagora MCP Server, so you can run agents against it safely.

FAQ

Questions about update_function

What does the update_function tool do? +

Update your function listing. Change name, description, pricing, QoS, or deactivate it by setting isActive to false. Only the owning provider can update a function. It is categorised as a Write tool in the Theagora 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 update_function? +

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

What risk level is update_function? +

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

Can I rate-limit update_function? +

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

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

update_function is provided by the Theagora MCP Server MCP server (theagoralabs/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.