Get the balances of all fungible tokens for a Flow address, The flow address is 16 characters long or 18 characters long with 0x prefix NOTE: This is a flow blockchin tool, not for flow EVM chain.
AI agents call get_token_balances to retrieve information from Flow MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries token balance data for a specified Flow address without any side effects, data modification, or irreversible operations. It is a straightforward data retrieval function analogous to checking account balances, which poses minimal risk even if misused by an AI agent—the worst outcome would be unauthorized information disclosure about token holdings, not financial loss or asset movement.
From the tool's definition Tool name 'get_token_balances' and description 'Get the balances of all fungible tokens for a Flow address' indicate a read-only query operation with no modification or execution capabilities.
Attacks that exploit this kind of access
Get the balances of all fungible tokens for a Flow address, The flow address is 16 characters long or 18 characters long with 0x prefix NOTE: This is a flow blockchin tool, not for flow EVM chain. It is categorised as a Read tool in the Flow MCP MCP Server, which means it retrieves data without modifying state.
Register the Flow MCP server in PolicyLayer and add a rule for get_token_balances: 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 Flow MCP. Nothing to install.
get_token_balances 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 get_token_balances 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 get_token_balances. 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.
get_token_balances is provided by the Flow MCP server (outblock/flow-mcp-monorepo). 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.
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