postgres-mcp

list_tables

Get a list of tables, views, and materialized views in a schema, including comments, estimated row counts, and on-disk sizes.

Instructions

List tables, partitioned tables, views and materialized views in a schema, with comment, estimated row count and on-disk size.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_tables"
  }
}

Input Schema

Name	Required	Description	Default
`schema`	No		public

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Jun 21, 2026

TDQS

B3.4/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It discloses that the operation is a read (list) and mentions the output fields (comment, row count, size), but does not address potential behavior like filtering by schema (defaults to 'public'), performance implications, or permission requirements.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-framed sentence of about 20 words. It immediately states the action and the object types, then adds output details. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple list tool with one parameter and an output schema, the description covers the basic purpose and return info. However, given the number of siblings, more explicit differentiation or behavioral notes (e.g., 'does not include system schemas') would improve completeness. The output schema likely covers return fields, so that part is adequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema parameter has no description in the input schema (0% coverage). The tool description adds context by saying 'in a schema', implying the parameter specifies the namespace, but it does not explain the default value 'public' or what happens if omitted. More detail is needed to fully compensate for the missing schema description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb 'List' and specifies the exact resource set: tables, partitioned tables, views, and materialized views within a schema. It also mentions the output includes comment, estimated row count, and on-disk size, which distinguishes it from siblings like 'list_views' (only views) or 'describe_table' (single table details).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit guidance on when to use this tool versus its siblings (e.g., 'list_views' for only views, 'describe_table' for detailed schema). The description only states what it does, not when or when not to use it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server