MCP PostgreSQL Operations

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

With no annotations provided, the description carries full burden. It clearly describes this as a read-only retrieval operation (not creation/deletion), specifies the return format as 'Table-format information', and outlines what information is included. It doesn't mention rate limits, authentication requirements, or pagination behavior, but provides substantial behavioral context.

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 uses clear section headers ([Tool Purpose], [Exact Functionality], etc.) making it easy to scan. While slightly verbose with bullet points, every section adds value and there's no redundant information. The structure helps the agent quickly understand different aspects of the tool.

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 zero-parameter tool with an output schema (which handles return value documentation), the description provides excellent context. It covers purpose, functionality, use cases, prohibitions, and return format. Given the tool's simplicity and the presence of output schema, this description is complete and well-balanced.

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 tool has 0 parameters with 100% schema description coverage. The description appropriately doesn't discuss parameters since none exist. A baseline of 4 is appropriate for zero-parameter tools where the schema fully documents the absence of parameters.

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 explicitly states the tool's purpose as 'Retrieve list of all user accounts and permission information on PostgreSQL server' with specific details about what information is included (superuser status, permissions, creation/expiration dates). It clearly distinguishes this from sibling tools like get_database_list or get_table_list by focusing specifically on user accounts.

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 explicit 'Required Use Cases' (user list requests, permission management, security inspection, account status overview) and 'Strictly Prohibited Use Cases' (password information, user creation/deletion, session/activity history). This gives clear guidance on when to use this tool versus alternatives.

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