change_database

THE RISK

Medium Risk

Why change_database needs a policy

Changing the active database connection modifies the server's state by switching which database is used for subsequent queries. This is a Write-level action as it alters configuration/session state reversibly (you can switch back). The blast radius is medium because an agent misusing this could cause queries to run against the wrong database, potentially exposing unintended data or corrupting results.

From the tool's definition Connect to a different DuckDB database file

Documented attack patterns abuse exactly the kind of access change_database gives an agent:

POLICY

How to control change_database

PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Data Visualization Server, and nothing reaches the server without passing your rules. This is the rule we recommend for change_database:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "change_database": {
      "limits": [
        {
          "counter": "change_database_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

change_database stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register MCP Data Visualization Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MCP Data Visualization Server tools

Execute query_data Execute a SQL query on the database and return results Write load_csv_data Load CSV file into the database as a new table Write configure_chart Configure chart parameters by answering column selection questions Write create_interactive_dashboard Generate an interactive HTML dashboard with filtering controls and multiple visualizations Write create_sample_chart Create a sample chart for testing (useful for development) Write create_visualization Start creating a data visualization from natural language request Write select_database_by_number Select a database by its number from the browse results Write select_downloads_database_by_number Select a database by its number from the Downloads browse results

All 28 MCP Data Visualization Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about change_database

What does the change_database tool do? +

Connect to a different DuckDB database file. It is categorised as a Write tool in the MCP Data Visualization Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on change_database? +

Register the MCP Data Visualization Server MCP server in PolicyLayer and add a rule for change_database: 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 Data Visualization Server. Nothing to install.

What risk level is change_database? +

change_database is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit change_database? +

Yes. Add a rate_limit block to the change_database 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.

How do I block change_database completely? +

Set action: deny in the PolicyLayer policy for change_database. 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.

What MCP server provides change_database? +

change_database is provided by the MCP Data Visualization Server MCP server (xoniks/mcp-visualization-duckdb). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MCP Data Visualization Server tool call.

Start from MCP Data Visualization Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →