List all schemas in the current database. Requires active connection (use switch_server_db first). Optionally use server/database/schema params for one-time execution on a different server without changing the main connection.
AI agents call list_schemas to retrieve information from Postgres without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a straightforward schema enumeration/metadata query. It queries database structure information without creating, modifying, deleting, or executing any code. The 'list' verb and read-only nature clearly place it in the Read category.
From the tool's definition Tool description states it 'List all schemas in the current database' — a retrieval operation with no side effects. No modifications, deletions, or external operations are performed.
Attacks that exploit this kind of access
List all schemas in the current database. Requires active connection (use switch_server_db first). Optionally use server/database/schema params for one-time execution on a different server without changing the main connection. It is categorised as a Read tool in the Postgres MCP Server, which means it retrieves data without modifying state.
Register the Postgres MCP server in PolicyLayer and add a rule for list_schemas: 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 Postgres. Nothing to install.
list_schemas 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 list_schemas 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 list_schemas. 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.
list_schemas is provided by the Postgres MCP server (teja-sudo/postgres-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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