list_tablesDiscover table names in a PostgreSQL schema (default: public) to identify available tables before querying.
List all tables in a schema (default: 'public'). Use this before querying tables you have not seen yet, then call describe_table for column details. Returns {tables: [name, ...]}.
| Name | Required | Description | Default |
|---|---|---|---|
| schema | No | Schema name (default: 'public') |
Changes observed during successful MCP inspections.
v0.3.0Input schema / $schemaAdded value: +"http://json-schema.org/draft-07/schema#"Input schema / additionalPropertiesAdded value: +falseInput schema / properties / schema / descriptionPrevious value: -"Schema name (default: public)"New value: +"Schema name (default: 'public')"Input schema / requiredRemoved value: -[]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint=true, so the read-only nature is established. The description adds useful behavioral context beyond that: the default schema behavior and the exact return shape {tables: [name, ...]}, which is valuable because there is no 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.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three sentences with no wasted words: the first states purpose and default, the second gives usage guidance, and the third documents the return format. It is front-loaded and every sentence earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
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 optional parameter and annotations covering safety, the description is complete. It tells the agent what the tool does, when to use it, what the default is, and what the response looks like, so nothing essential is missing.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, and the schema already documents the single optional schema parameter with its default value. The description repeats the default-public behavior, so it adds no meaning beyond what the input schema provides.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb and resource: 'List all tables in a schema (default: 'public')'. It also distinguishes itself from the sibling describe_table by noting that describe_table should be used afterward for column details, making the tool's role clear.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It explicitly says to use the tool before querying tables not yet seen, and directs the agent to call describe_table next for column details. This provides clear when-to-use guidance and names the relevant alternative.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.