Look up details for a UK postcode.
AI agents call lookup_postcode to retrieve information from GovUK MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves publicly available postcode information from UK government data sources. It performs a lookup query without modifying, deleting, or executing any operations. The data retrieved is typically public geographic and administrative information. No financial transactions, code execution, or irreversible changes are involved, making this a straightforward Read category tool with low severity risk.
From the tool's definition Tool name 'lookup_postcode' and description 'Look up details for a UK postcode' indicate a query/retrieval operation.
Attacks that exploit this kind of access
Look up details for a UK postcode. It is categorised as a Read tool in the GovUK MCP Server MCP Server, which means it retrieves data without modifying state.
Register the GovUK MCP Server MCP server in PolicyLayer and add a rule for lookup_postcode: 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 GovUK MCP Server. Nothing to install.
lookup_postcode 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_postcode 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_postcode. 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_postcode is provided by the GovUK MCP Server MCP server (stealth-labs-ltd/govuk-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
lookup_postcode is one line of GovUK 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.
Teams ship this data inside their own products. See what a licence covers →