AI agents call lookup_hash to retrieve information from Satsignal without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
lookup_hash retrieves information from the blockchain without modifying, creating, deleting, or executing any operations. It is purely a data lookup/verification tool that returns whether a hash exists on-chain. This is a classic Read category operation with minimal risk—the worst outcome of misuse would be an agent checking hashes it shouldn't, without affecting any assets or data integrity.
From the tool's definition Tool description states 'Read-only' and the operation is to 'Check whether a sha256 is anchored on-chain', which is a query operation with no side effects.
Attacks that exploit this kind of access
Check whether a sha256 is anchored on-chain. Read-only,. It is categorised as a Read tool in the Satsignal MCP Server, which means it retrieves data without modifying state.
Register the Satsignal MCP server in PolicyLayer and add a rule for lookup_hash: 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 Satsignal. Nothing to install.
lookup_hash 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 lookup_hash 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 lookup_hash. 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.
lookup_hash is provided by the Satsignal MCP server (steleet/satsignal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →