list_tables

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It specifies the output (list of tables with description and row count) and notes 'No SQL is required,' implying a read-only metadata operation. However, it does not explicitly state that the operation is read-only or side-effect-free, nor does it mention any authentication or performance considerations, which are minor for a simple listing 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 two concise sentences. The first sentence states the action and output, and the second provides usage context. No filler words or redundancies exist, and the most important information (what it does) is front-loaded.

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 tool has no parameters, no output schema, and a simple, self-contained purpose, the description is complete. It tells the agent exactly what it will receive (tables, descriptions, row counts) and when to call it. Nothing critical is missing for effective use.

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 zero parameters, and the schema coverage is trivially 100%. Per the baseline rule for 0-parameter tools, a score of 4 is appropriate. The description adds value by explaining what the tool outputs, which fully compensates for 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 clearly states the tool lists all tables with a short description and row counts. It also differentiates itself from siblings by saying 'Use this first when you do not know the schema, before writing any SQL,' which implies it is a schema-discovery tool distinct from describe_table (specific table details) and read_query (SQL execution).

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 explicitly states when to use it ('when you do not know the schema' and 'before writing any SQL'), providing clear contextual guidance. It does not name alternative tools explicitly, but the context strongly implies that after gaining schema knowledge, one would use read_query or describe_table, which is sufficient for minimal guidance.

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