list_composite_types

A read tool on the Mcpg MCP server.

SERVERMcpg SOURCEpypi:mcpg

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-devopam-mcpg/list-composite-types.md

WHAT IT DOES

What list_composite_types does on Mcpg

AI agents call list_composite_types to retrieve information from Mcpg without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why list_composite_types is rated Low

The tool retrieves PostgreSQL composite type metadata through a read-only catalog query. There are no side effects, no data modification, no code execution, and no destructive operations. The empty description lowers confidence slightly, but the naming convention 'list_*' is a strong indicator of Read category operations. Listing composite types is a safe introspection activity typical of database inspection tools.

From the tool's definition Tool name 'list_composite_types' indicates a listing/enumeration operation. The 'list_' prefix strongly suggests data retrieval without modification. This is a PostgreSQL introspection function that queries system catalog information.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_composite_types safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Mcpg, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_composite_types, this is the rule to start with:

list_composite_types Allowed

list_composite_types is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

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

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Mcpg, apply this rule, and every list_composite_types call is checked against it from then on.

FAQ

Questions about list_composite_types

What does the list_composite_types tool do? +

list_composite_types is a read tool on the Mcpg MCP server. It is categorised as a Read tool in the Mcpg MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_composite_types? +

Register the Mcpg MCP server in PolicyLayer and add a rule for list_composite_types: 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 Mcpg. Nothing to install.

What risk level is list_composite_types? +

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

Can I rate-limit list_composite_types? +

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

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

list_composite_types is provided by the Mcpg MCP server (pypi:mcpg). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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