Computes areas that are reachable within a specified amount of time from a location, and returns the reachable regions as contours of Polygons or LineStrings in GeoJSON format that you can display on a map. Common use cases: - Show a user how far they can travel in X minutes from their current lo...
Risk signalsHigh parameter count (12 properties)
Part of the Mapbox server.
Free to start. No card required.
AI agents call isochrone_tool to retrieve information from Mapbox without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though isochrone_tool only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"isochrone_tool": {}
}
}See the full Mapbox policy for all 9 tools.
These attack patterns abuse exactly the kind of access isochrone_tool gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Computes areas that are reachable within a specified amount of time from a location, and returns the reachable regions as contours of Polygons or LineStrings in GeoJSON format that you can display on a map. Common use cases: - Show a user how far they can travel in X minutes from their current location - Determine whether a destination is within a certain travel time threshold - Compare travel ranges for different modes of transportation'. It is categorised as a Read tool in the Mapbox MCP Server, which means it retrieves data without modifying state.
Register the Mapbox MCP server in PolicyLayer and add a rule for isochrone_tool: 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 Mapbox. Nothing to install.
isochrone_tool 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 isochrone_tool 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 isochrone_tool. 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.
isochrone_tool is provided by the Mapbox MCP server (Waldzell-Agentics/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 9 Mapbox tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.