Returns Keccak-256 hash of the given data
AI agents call web3_sha3 to retrieve information from EVM MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a deterministic hash computation utility that takes input data and returns a hash output. It performs no reads from blockchain state, makes no modifications, executes no external code or commands, and has no destructive or financial implications. It is purely a read/compute operation on caller-supplied data. Typical use cases (message signing, data verification) confirm this is a safe utility function.
From the tool's definition Tool name 'web3_sha3' and description 'Returns Keccak-256 hash of the given data' indicates a pure cryptographic hash function with no side effects, no state modification, no external operations triggered.
Attacks that exploit this kind of access
Returns Keccak-256 hash of the given data. It is categorised as a Read tool in the EVM MCP Server MCP Server, which means it retrieves data without modifying state.
Register the EVM MCP Server MCP server in PolicyLayer and add a rule for web3_sha3: 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 EVM MCP Server. Nothing to install.
web3_sha3 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 web3_sha3 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 web3_sha3. 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.
web3_sha3 is provided by the EVM MCP Server MCP server (jamesanz/evm-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
web3_sha3 is one line of EVM MCP Server's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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