Low Risk

ListMetrics

Get a list of all metric names. ## Usage - Use this tool to discover available metrics in the Prometheus server - Returns a sorted list of all metric names - Useful for exploration before crafting specific queries - If workspace_id is not known, use GetAvailableWorkspaces tool first to find avai...

Part of the Prometheus MCP Server MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

AI agents call ListMetrics to retrieve information from Prometheus MCP Server without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.

Even though ListMetrics only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.

Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.

prometheus-mcp-server.yaml
tools:
  ListMetrics:
    rules:
      - action: allow

See the full Prometheus MCP Server policy for all 5 tools.

Tool Name ListMetrics
Category Read
Risk Level Low

Agents calling read-class tools like ListMetrics have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.

What does the ListMetrics tool do? +

Get a list of all metric names. ## Usage - Use this tool to discover available metrics in the Prometheus server - Returns a sorted list of all metric names - Useful for exploration before crafting specific queries - If workspace_id is not known, use GetAvailableWorkspaces tool first to find available workspaces and ASK THE USER to choose one ## Example Input: workspace_id: "ws-12345678-abcd-1234-efgh-123456789012" region: "us-east-1" Output: { "metrics": [ "go_gc_duration_seconds", "go_goroutines", "http_requests_total", ... ] }. It is categorised as a Read tool in the Prometheus MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on ListMetrics? +

Add a rule in your Intercept YAML policy under the tools section for ListMetrics. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Prometheus MCP Server MCP server.

What risk level is ListMetrics? +

ListMetrics is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit ListMetrics? +

Yes. Add a rate_limit block to the ListMetrics rule in your Intercept 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 ListMetrics completely? +

Set action: deny in the Intercept policy for ListMetrics. 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 ListMetrics? +

ListMetrics is provided by the Prometheus MCP Server MCP server (awslabs.prometheus-mcp-server). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Let agents act without letting them run wild.

Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.

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