Verifies the authenticity and expiry of a sigil_token returned by sigil_verify_supply_path. Anyone can call this — no key needed; Sigil verifies the Ed25519 signature server-side. Tokens live 5 minutes. Returns valid (boolean), reason (when invalid: malformed / expired / bad_signature / unsigned)...
Risk signalsHandles credentials or secrets (token)
Part of the TunnelMind Data API server.
Free to start. No card required.
AI agents call sigil_verify_token to retrieve information from TunnelMind Data API 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 sigil_verify_token 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.
{
"version": "1",
"default": "deny",
"tools": {
"sigil_verify_token": {}
}
}See the full TunnelMind Data API policy for all 54 tools.
These attack patterns abuse exactly the kind of access sigil_verify_token gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Verifies the authenticity and expiry of a sigil_token returned by sigil_verify_supply_path. Anyone can call this — no key needed; Sigil verifies the Ed25519 signature server-side. Tokens live 5 minutes. Returns valid (boolean), reason (when invalid: malformed / expired / bad_signature / unsigned), and the decoded payload.. It is categorised as a Read tool in the TunnelMind Data API MCP Server, which means it retrieves data without modifying state.
Register the TunnelMind Data API MCP server in PolicyLayer and add a rule for sigil_verify_token: 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 TunnelMind Data API. Nothing to install.
sigil_verify_token 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 sigil_verify_token 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 sigil_verify_token. 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.
sigil_verify_token is provided by the TunnelMind Data API MCP server (https://mcp-data.tunnelmind.ai/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 54 TunnelMind Data API tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.