AI agents use close_all_positions to create or update resources in Alpaca MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Alpaca MCP Server environment.
An AI agent can call close_all_positions faster than any human can review — one bad instruction and it creates or modifies resources in Alpaca MCP Server by the hundred, each call as confident as the last.
Documented attack patterns abuse exactly the kind of access close_all_positions gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Alpaca MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for close_all_positions:
{
"version": "1",
"default": "deny",
"tools": {
"close_all_positions": {
"limits": [
{
"counter": "close_all_positions_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}close_all_positions 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.
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Close all open positions. It is categorised as a Write tool in the Alpaca MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Alpaca MCP Server MCP server in PolicyLayer and add a rule for close_all_positions: 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 Alpaca MCP Server. Nothing to install.
close_all_positions is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the close_all_positions 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.
Set action: deny in the PolicyLayer policy for close_all_positions. 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.
close_all_positions is provided by the Alpaca MCP Server MCP server (tedlikeskix/alpaca-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 9 Alpaca MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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9 Alpaca MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.