list_distinct_values

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 mentions counting distinct categories but doesn't specify if this is a read-only operation, performance implications, error handling, or output format. This leaves significant gaps for a tool that likely queries data.

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 single, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded and to the point, though it could be slightly more structured to clarify ambiguities.

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 no annotations and no output schema, the description is incomplete. It doesn't explain what 'distinct categories' means, how the column is selected, or what the return value looks like (e.g., count, list). For a tool with one parameter but unclear behavior, this is inadequate.

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 has 100% description coverage, with 'table_name' clearly documented. The description adds minimal value beyond the schema by implying a column is involved but doesn't specify which column or provide additional context. Baseline 3 is appropriate as the schema handles the parameter documentation.

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 states the tool counts distinct categories for a column in a table, which is a clear purpose. However, it doesn't specify which column or how it determines 'categories,' making it somewhat vague. It distinguishes from siblings like list_tables or query but could be more specific.

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?

No guidance is provided on when to use this tool versus alternatives such as list_missing_values or standard_deviation. The description implies usage for counting distinct categories but doesn't mention prerequisites, exclusions, or specific scenarios, leaving the agent without clear direction.

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