expected_value
Expected Value & Variance — E[X], variance and standard deviation of a discrete distribution.
This record as markdown: /tools/com-wingmanprotocol-agent-gateway/expected-value.md
What expected_value does on Gateway
AI agents call expected_value to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
outcomes | array | Yes | Array of numeric payoffs |
probabilities | array | Yes | Probabilities (same length, sum to 1) |
Parameters from the server's own tool schema.
Why expected_value is rated Low
This is a mathematical utility that reads input values and returns computed statistical measures. It has no side effects, does not modify any data, and does not trigger external operations. It belongs in the Read category with low severity, as misuse would at worst produce incorrect financial or risk calculations, but the tool itself performs no irreversible or dangerous actions.
From the tool's definition Tool computes mathematical statistics (E[X], variance, standard deviation) on discrete distributions. No modification, deletion, or execution of external operations occurs. Pure calculation and retrieval of statistical properties.
Attacks that exploit this kind of access
The rule that runs expected_value safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For expected_value, this is the rule to start with:
expected_value is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Gateway, apply this rule, and every expected_value call is checked against it from then on.
Questions about expected_value
Expected Value & Variance — E[X], variance and standard deviation of a discrete distribution. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.
expected_value accepts 2 parameters: outcomes, probabilities. Required: outcomes, probabilities. The full parameter table on this page comes from the server's own tool schema.
Register the Gateway MCP server in PolicyLayer and add a rule for expected_value: 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 Gateway. Nothing to install.
expected_value 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 expected_value 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 expected_value. 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.
expected_value is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Gateway, and thousands of servers like it.
This server
Across the catalogue