unfour

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List Database Tables

unfour.db.list_tables

Read-onlyIdempotent

Lists tables and views for a saved database connection using its connectionId, with optional catalog and schema filters. Helps explore database structure without ad-hoc connection strings.

Instructions

Lists tables and views for a saved database connection through the Unfour command bus. Optional catalog and schema scope the listing. Requires a saved connectionId; does not accept ad-hoc connection strings.

Input Schema

TableJSON Schema

Name	Required	Description
`limit`	No	Maximum number of tables to return (default 200, max 500).
`schema`	No	Optional schema name. pg_catalog and information_schema are excluded even when specified.
`catalog`	No	Optional database catalog. Omit to use the connection's default database.
`workspaceId`	No	Optional workspace ID. Uses the active workspace if omitted.
`connectionId`	Yes	Required saved database connection ID.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`count`	Yes
`source`	Yes
`tables`	Yes
`truncated`	Yes
`totalTables`	Yes
`connectionId`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.10.0Sep 30, 2026

addedInput schema / properties / catalog

Added value: +{
+  "description": "Optional database catalog. Omit to use the connection's default database.",
+  "type": "string"
+}

addedInput schema / properties / schema

Added value: +{
+  "description": "Optional schema name. pg_catalog and information_schema are excluded even when specified.",
+  "type": "string"
+}

Changed1 schema field changedv0.6.0Aug 22, 2026
- addedOutput schema / properties / tables / items / properties / catalog
```
Added value: +{
+  "type": [
+    "string",
+    "null"
+  ]
+}
```
First observedv0.1.0Aug 20, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds meaningful context beyond that: the operation runs through the 'Unfour command bus' and is restricted to saved connections, which is a real operational constraint. It adds little else (no pagination/return behavior), but that is largely carried by the output schema.

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?

Three short sentences, front-loaded with the core action, then scoping parameters, then the connection constraint. No filler or restatement of the title.

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

Completeness4/5

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

With an output schema, rich annotations and fully documented parameters, the description only needs to establish scope and prerequisites, which it does. The one remaining gap is that it does not hint at result ordering or the effect of the limit parameter, but that is minor given the schema coverage.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema already documents limit, schema, catalog, workspaceId and connectionId in detail. The description only restates that catalog and schema scope the listing and that connectionId is required, adding no syntax or format information beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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

Purpose4/5

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

States a specific verb (Lists) and resource (tables and views) scoped to a saved database connection, which clearly separates it from siblings like unfour.db.describe_table and unfour.db.query_readonly. It does not explicitly name a sibling, but the resource scope makes the intent unmistakable.

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

Usage Guidelines4/5

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

Gives a clear precondition (requires a saved connectionId) and an explicit exclusion (does not accept ad-hoc connection strings), which tells the agent when this tool applies versus constructing a new connection. It stops short of naming an alternative tool for the ad-hoc case, so it is strong but not exhaustive.

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

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