# mcp_server_unreachable

**HTTP status:** 422 (Unprocessable)

**Title:** MCP server unreachable

## Cause

The MCP server did not answer a tools request. Check the URL and the credentials. Redirects are not followed.

## How to fix it

Check the URL and credentials of the MCP server. The URL must answer a tools request without redirecting.

Set the parameter named below and send the request again.

Parameter: `url`

Every error carries `requestId` and the `Request-Id` header. Send it when you write to support.

[All error codes](/errors)