MCP PostgreSQL Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool lists tables, implying a read-only operation, but doesn't specify whether it returns all tables, includes system tables, requires specific permissions, or handles errors. This leaves significant gaps in understanding the tool's behavior beyond the basic action.

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?

The description is extremely concise—a single, clear sentence that directly states the tool's purpose without any unnecessary words. It is front-loaded and efficiently communicates the core functionality, making it easy to parse quickly.

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?

Given the lack of annotations and output schema, the description is incomplete for a tool that interacts with a database. It doesn't address key contextual aspects like what the output looks like (e.g., a list of table names, metadata), error conditions, or dependencies on other tools (e.g., 'connect_db'). This leaves the agent with insufficient information to use the tool effectively in complex scenarios.

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?

The input schema has 100% description coverage, with the single parameter 'schema' documented as 'Schema name (default: public)'. The description adds no additional meaning about parameters beyond what the schema provides, such as explaining the significance of the schema parameter or how it affects the listing. With high schema coverage, the baseline score of 3 is appropriate.

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 clearly states the action ('List') and resource ('tables in the database'), making the tool's purpose immediately understandable. However, it doesn't differentiate from sibling tools like 'list_schemas' or 'describe_table', which would require specifying what makes this listing operation unique.

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?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing a database connection via 'connect_db'), nor does it explain how it differs from 'list_schemas' (which might list schemas instead of tables) or 'describe_table' (which might provide detailed metadata).

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