MCP PostgreSQL Server

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

No annotations are provided, so the description carries full burden. It states the tool executes queries but doesn't disclose critical behavioral traits: whether it requires authentication, what permissions are needed, if changes are reversible, transaction behavior, error handling, or what happens on success/failure. For a mutation tool with zero annotation coverage, this is a significant gap.

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 (one sentence) with zero waste. It's front-loaded with the core purpose and includes essential parameter syntax guidance. Every word 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?

Given this is a mutation tool with no annotations and no output schema, the description is incomplete. It doesn't explain what happens after execution (e.g., returns row count, success/failure, error messages), security implications, or transactional behavior. For a tool that modifies data, this leaves critical gaps.

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 100%, so the schema already documents both parameters (sql and params) with their types and purposes. The description adds minimal value beyond what the schema provides, mentioning the same query types and parameter placeholders ($1, $2). Baseline 3 is appropriate when schema does the heavy lifting.

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 executes SQL queries (INSERT, UPDATE, DELETE), providing specific verb+resource. It distinguishes from the 'query' sibling tool by specifying the types of queries it handles (data manipulation vs. likely SELECT queries). However, it doesn't explicitly mention database operations or contrast with all siblings like 'connect_db'.

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 implies usage for data modification queries (INSERT/UPDATE/DELETE) versus the 'query' tool likely for SELECT queries, but doesn't explicitly state when to use this tool versus alternatives. No guidance on prerequisites (like needing an established connection) or exclusions is provided.

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