get_schema

THE RISK

Low Risk

Why get_schema needs a policy

This tool retrieves schema metadata about the database structure—tables, columns, types, constraints, etc.—without executing queries, modifying data, or triggering side effects. It is purely informational and supports inspection use cases.

From the tool's definition Tool name 'get_schema' and description 'Get database schema information' indicate data retrieval with no modification or execution. The verb 'Get' and the focus on retrieving schema metadata (structure, not data operations) confirm read-only behavior.

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

POLICY

How to control get_schema

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "get_schema": {}
  }
}

get_schema is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

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

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MCP SQL Server tools

Destructive clear_caches Initialize cache data Execute execute_query Execute SQL queries Execute start_batch_processing Process multiple queries in batch Execute start_performance_monitoring Start performance monitoring Read describe_table Get structure of a specific table Read get_connection_pool_status Get database connection pool status Read get_query_stats Get query execution statistics Read get_schema_statistics Get schema statistics information

All 11 MCP SQL Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about get_schema

What does the get_schema tool do? +

Get database schema information. It is categorised as a Read tool in the MCP SQL Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_schema? +

Register the MCP SQL Server MCP server in PolicyLayer and add a rule for get_schema: 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 SQL Server. Nothing to install.

What risk level is get_schema? +

get_schema is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit get_schema? +

Yes. Add a rate_limit block to the get_schema 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 get_schema completely? +

Set action: deny in the PolicyLayer policy for get_schema. 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 get_schema? +

get_schema is provided by the MCP SQL Server MCP server (ryudg/mcp-sql). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MCP SQL Server tool call.

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

CHECK YOUR STACK →