MCP Postgres 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 reveals important behavioral traits like pagination support, parameterization for security, and the 500-row page size limit, but doesn't cover other critical aspects like authentication requirements, rate limits, transaction behavior, or error handling.

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 perfectly concise with two sentences that each earn their place: the first establishes core functionality, the second adds important constraints. It's front-loaded with the primary purpose and wastes no words.

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 complex SQL execution tool with 4 parameters, no annotations, and no output schema, the description is incomplete. While it covers the basic purpose and some constraints, it lacks information about return values, error conditions, transaction scope, and other behavioral details needed for safe usage.

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 description coverage is 75% (3 of 4 parameters have descriptions), so the baseline is 3. The description adds some value by mentioning 'pagination support' (relevant to offset and pageSize) and 'parameterization for security' (relevant to parameters), but doesn't provide additional semantic context beyond what's in the schema descriptions.

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 tool's purpose with specific verbs ('Execute SQL queries') and resources ('SQL queries'), distinguishing it from sibling tools that focus on metadata retrieval (like list_tables, describe_table) rather than query execution. It explicitly mentions key capabilities like pagination and parameterization.

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 clear context for when to use this tool (for executing SQL queries with pagination and security features), but doesn't explicitly state when NOT to use it or name specific alternatives among the sibling tools. It implies usage for query execution versus metadata operations.

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