position_update · Stock MCP Server MCP: Risk & Policy

WHAT IT DOES

What position_update does on Stock MCP Server

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

WHY IT NEEDS A POLICY

Why position_update needs a policy

This tool modifies user stock position records (quantity and cost price), which are reversible changes. It does not delete data (Destructive), execute arbitrary operations (Execute), or move money (Financial). However, severity is high because incorrect position updates could lead to miscalculated portfolio values, incorrect tax reporting, or confused trading decisions that cause financial loss.

From the tool's definition Tool name 'position_update' combined with description '更新持仓记录（数量或成本价）' (update position record - quantity or cost price) indicates modification of existing financial position data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

position_update Rate-limited

position_update 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": {
    "position_update": {
      "limits": [
        {
          "counter": "position_update_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 Stock MCP Server, so you can run agents against it safely.

FAQ

Questions about position_update

What does the position_update tool do? +

更新持仓记录（数量或成本价）. It is categorised as a Write tool in the Stock 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 position_update? +

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

What risk level is position_update? +

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

Can I rate-limit position_update? +

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

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

position_update is provided by the Stock MCP Server MCP server (kinmeic/stock-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.