buy_stock_limit

Places a limit buy order for a stock.

SERVEROpen Stocks MCP SOURCEopen-agent-tools/open-stocks-mcp

Critical RISK CLASS

Category Financial

Parameters 00 required

Recommended Approval-gatedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/open-agent-tools-open-stocks-mcp/buy-stock-limit.md

WHAT IT DOES

What buy_stock_limit does on Open Stocks MCP

AI agents use buy_stock_limit to commit financial operations through Open Stocks MCP, usually the final step of a payment, billing, or trading workflow. A call moves real money.

RISK

Why buy_stock_limit is rated Critical

This tool directly executes a financial transaction by placing a buy order through a broker API (Robinhood/Schwab). It commits real financial obligations by purchasing stock at a specified limit price. Misuse could result in unauthorized trades and significant financial loss.

From the tool's definition Places a limit buy order for a stock

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs buy_stock_limit safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Open Stocks MCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For buy_stock_limit, this is the rule to start with:

buy_stock_limit Approval-gated

Any call to buy_stock_limit is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "buy_stock_limit": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

GATE THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Open Stocks MCP, apply this rule, and every buy_stock_limit call is checked against it from then on.

FAQ

Questions about buy_stock_limit

What does the buy_stock_limit tool do? +

Places a limit buy order for a stock. It is categorised as a Financial tool in the Open Stocks MCP MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on buy_stock_limit? +

Register the Open Stocks MCP server in PolicyLayer and add a rule for buy_stock_limit: 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 Open Stocks MCP. Nothing to install.

What risk level is buy_stock_limit? +

buy_stock_limit is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit buy_stock_limit? +

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

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

buy_stock_limit is provided by the Open Stocks MCP server (open-agent-tools/open-stocks-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Open Stocks, and thousands of servers like it.

This server

All 152 Open Stocks tools → Critical-risk tools on this server →

Across the catalogue

place_limit_order on Lighter MCP →buy_now on Ebay → All critical-risk MCP tools → The MCP Attack Database →

Guides

Govern MCP payment tools →Human-in-the-loop →Tool call approval →