Check if an address has a specific role on a TIP-20 token.
AI agents call has_role to retrieve information from Tempo without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves role information about an address on a blockchain token contract. It performs a read-only query with no side effects: it does not execute code, create/modify/delete data, move funds, or trigger external operations. While it exists on a financial payment system (Tempo blockchain stablecoin), the tool itself only checks and returns existing role data.
From the tool's definition Tool name is 'has_role' and description states it 'Check if an address has a specific role on a TIP-20 token' — a pure query operation with no state modifications.
Documented attack patterns abuse exactly the kind of access has_role gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Tempo, and nothing reaches the server without passing your rules. This is the rule we recommend for has_role:
{
"version": "1",
"default": "deny",
"tools": {
"has_role": {}
}
}has_role is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check if an address has a specific role on a TIP-20 token. It is categorised as a Read tool in the Tempo MCP Server, which means it retrieves data without modifying state.
Register the Tempo MCP server in PolicyLayer and add a rule for has_role: 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 Tempo. Nothing to install.
has_role 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 has_role 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 has_role. 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.
has_role is provided by the Tempo MCP server (arome3/tempo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Tempo, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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61 Tempo tools catalogued and risk-classified — across an index of 43,000+ MCP servers.