OSM Taginfo: list the most common values for an OpenStreetMap key, by frequency (e.g. all amenity= values from "parking" down). Useful for understanding how features are tagged in OSM. Keyless.
AI agents call key_values to retrieve information from Mcp Taginfo without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
key | string | Yes | An OSM key, e.g. "amenity", "highway", "cuisine". |
limit | number | — | Max values to return (default 20, max 100). |
Parameters from the server's own tool schema.
This tool retrieves and queries OpenStreetMap tag statistics without any side effects. It is a straightforward data retrieval operation that has no impact on the underlying data or external systems. The severity is low because misuse would only surface incorrect or irrelevant tag frequency information to an AI agent, with no destructive, financial, or system-altering consequences.
From the tool's definition Tool description states 'list the most common values' and 'Useful for understanding how features are tagged in OSM'. The word 'list' indicates retrieval of data. No mention of modification, deletion, code execution, or financial operations.
Attacks that exploit this kind of access
OSM Taginfo: list the most common values for an OpenStreetMap key, by frequency (e.g. all amenity= values from "parking" down). Useful for understanding how features are tagged in OSM. Keyless. It is categorised as a Read tool in the Mcp Taginfo MCP Server, which means it retrieves data without modifying state.
key_values accepts 2 parameters: key, limit. Required: key. The full parameter table on this page comes from the server's own tool schema.
Register the Mcp Taginfo MCP server in PolicyLayer and add a rule for key_values: 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 Mcp Taginfo. Nothing to install.
key_values 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 key_values 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 key_values. 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.
key_values is provided by the Mcp Taginfo MCP server (pipeworx-io/mcp-taginfo). 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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