AI agents call list_datasources to retrieve information from Grafana FastMCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool lists datasources, which is a read-only retrieval operation that queries existing Grafana configuration without modifying or executing anything. Even if datasource details are sensitive, listing them has minimal blast radius compared to creation, modification, or deletion. Low severity due to read-only nature and no side effects.
From the tool's definition Tool name is 'list_datasources' which by naming convention and context of Grafana observability server performs a query/listing operation. Description is empty, but sibling tools and server context indicate this retrieves datasource configuration from Grafana.
Documented attack patterns abuse exactly the kind of access list_datasources gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Grafana FastMCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_datasources:
{
"version": "1",
"default": "deny",
"tools": {
"list_datasources": {}
}
}list_datasources is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
list_datasources. It is categorised as a Read tool in the Grafana FastMCP Server MCP Server, which means it retrieves data without modifying state.
Register the Grafana FastMCP Server MCP server in PolicyLayer and add a rule for list_datasources: 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 Grafana FastMCP Server. Nothing to install.
list_datasources 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 list_datasources 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 list_datasources. 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.
list_datasources is provided by the Grafana FastMCP Server MCP server (sandersouza/grafanafastmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Grafana FastMCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
45 Grafana FastMCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.