Get the schema for the graph including the vertex and edge labels as well as the
AI agents call get_graph_schema to retrieve information from Prometheus MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves schema metadata (vertex and edge labels) from a graph. It is a read-only operation that queries existing structure without side effects, modifications, or execution of arbitrary operations. No data is created, deleted, or executed—only schema information is fetched.
From the tool's definition Tool name 'get_graph_schema' and description 'Get the schema for the graph including the vertex and edge labels' indicate retrieval of metadata/schema information with no data modification or execution.
Documented attack patterns abuse exactly the kind of access get_graph_schema gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Prometheus MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_graph_schema:
{
"version": "1",
"default": "deny",
"tools": {
"get_graph_schema": {}
}
}get_graph_schema is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get the schema for the graph including the vertex and edge labels as well as the. It is categorised as a Read tool in the Prometheus MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Prometheus MCP Server MCP server in PolicyLayer and add a rule for get_graph_schema: 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 Prometheus MCP Server. Nothing to install.
get_graph_schema 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 get_graph_schema 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 get_graph_schema. 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.
get_graph_schema is provided by the Prometheus MCP Server MCP server (awslabs.prometheus-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Prometheus MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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805 Prometheus MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.