Get the balance for a specific account. Shows both cleared balance (settled transactions) and effective balance (including pending transactions).
AI agents call account_balance_get to retrieve information from Starling Bank without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves financial account balance information with no side effects. While it accesses sensitive financial data, the read-only nature and lack of capability to move money, modify data, or trigger irreversible actions places it in the Read category. Severity is low because viewing account balance alone poses minimal risk—an agent cannot cause financial harm merely by reading a balance.
From the tool's definition Tool name 'account_balance_get' and description 'Get the balance for a specific account' indicate a read-only query operation that retrieves account balance data without modifying, deleting, or executing any operations.
Attacks that exploit this kind of access
Get the balance for a specific account. Shows both cleared balance (settled transactions) and effective balance (including pending transactions). It is categorised as a Read tool in the Starling Bank MCP Server, which means it retrieves data without modifying state.
Register the Starling Bank MCP server in PolicyLayer and add a rule for account_balance_get: 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 Starling Bank. Nothing to install.
account_balance_get 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 account_balance_get 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 account_balance_get. 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.
account_balance_get is provided by the Starling Bank MCP server (starling-bank-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.
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