run_query

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

With no annotations provided, the description fully covers behavioral details: parsing with real PostgreSQL grammar, access policy check, read-only transaction, statement timeout, row cap, and error messages that name the denying rule. This is comprehensive for a query execution tool.

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 a concise three-sentence paragraph, front-loaded with the core purpose. Every sentence adds distinct value: purpose, execution details, and error reporting. No unnecessary 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?

Given the single parameter with full schema coverage and no output schema, the description adequately covers purpose, behavior, and constraints. However, it does not explicitly describe the return format (e.g., rows as JSON), which might be assumed but is not stated.

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 already provides a detailed description for the 'sql' parameter (100% coverage). The tool description adds context about the execution environment (read-only transaction, timeout, row cap) and error behavior, which supplements the schema without repeating it.

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 begins with 'Run one read-only SELECT against the allowlisted tables,' which clearly states the action (run), the resource (SELECT query on tables), and the scope (allowlisted, read-only). This distinguishes it from sibling tools like 'list_tables' or 'sample_rows' that handle different operations.

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 specifies that the tool only accepts read-only SELECT statements and details what is rejected (DML, DDL, multiple statements, etc.). While it does not explicitly name alternative tools for those cases, the constraints make the appropriate usage clear.

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