AI agents call list_pallets to retrieve information from Substrate 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 a read-only query of runtime metadata. It retrieves and displays available pallets without modifying data, executing external code, or causing state changes. The operation is informational only, making it a Read category risk with low severity.
From the tool's definition Tool name is 'list_pallets' and description states 'List all pallets in the runtime' — a query operation that retrieves information about runtime pallets with no side effects or mutations.
Documented attack patterns abuse exactly the kind of access list_pallets gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Substrate MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_pallets:
{
"version": "1",
"default": "deny",
"tools": {
"list_pallets": {}
}
}list_pallets 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 all pallets in the runtime. It is categorised as a Read tool in the Substrate MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Substrate MCP Server MCP server in PolicyLayer and add a rule for list_pallets: 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 Substrate MCP Server. Nothing to install.
list_pallets 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_pallets 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_pallets. 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_pallets is provided by the Substrate MCP Server MCP server (thomasmarches/substrate-mcp-rs). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Substrate MCP 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.
13 Substrate MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.