The Hilbert Transform Sine Wave (HT_SINE) indicator calculates sine and cosine wave components based on the dominant market cycle, helping traders identify potential turning points and trend direction. You can read more about it in the Rocket Science for Traders book by John F. Ehlers.
AI agents call GetTimeSeriesHtSine to retrieve information from Twelve Data MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs technical analysis calculations on historical market data to generate trading indicators. It reads time series data and applies a mathematical transformation (Hilbert Transform) to produce analytical output. There are no side effects, no data modification, no irreversible actions, and no financial transactions.
From the tool's definition Tool description indicates it 'calculates sine and cosine wave components' and 'helps traders identify potential turning points', which are analytical operations that retrieve and process financial data without modifying, deleting, or executing external…
Documented attack patterns abuse exactly the kind of access GetTimeSeriesHtSine gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Twelve Data MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for GetTimeSeriesHtSine:
{
"version": "1",
"default": "deny",
"tools": {
"GetTimeSeriesHtSine": {}
}
}GetTimeSeriesHtSine is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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The Hilbert Transform Sine Wave (HT_SINE) indicator calculates sine and cosine wave components based on the dominant market cycle, helping traders identify potential turning points and trend direction. You can read more about it in the Rocket Science for Traders book by John F. Ehlers. It is categorised as a Read tool in the Twelve Data MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Twelve Data MCP Server MCP server in PolicyLayer and add a rule for GetTimeSeriesHtSine: 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 Twelve Data MCP Server. Nothing to install.
GetTimeSeriesHtSine is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the GetTimeSeriesHtSine 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 GetTimeSeriesHtSine. 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.
GetTimeSeriesHtSine is provided by the Twelve Data MCP Server MCP server (twelvedata/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 186 Twelve Data MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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186 Twelve Data MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.