get_castable_columns

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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description adds valuable behavioral context beyond that: missing tables return a structured not_found with two specific causes instead of a raw HTTP error. This informs the agent about error handling and edge cases.

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 efficient sentences: the first states the core purpose and output, the second adds a targeted edge-case behavior. Every word earns its place with no redundancy.

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 read-only metadata tool with rich annotations, a complete input schema, and an output schema, the description provides purpose, output shape, and key error behavior. It lacks explicit comparison with sibling tools, but the name and content are sufficient for correct selection.

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 covers 100% of parameters with clear descriptions, so the description does not need to add parameter-level detail. It neither repeats nor expands on the schema, but the schema is sufficient, supporting the baseline score of 3.

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 a specific verb ('Get') and resource ('column metadata for a CAS table') and enumerates the exact output fields (names, types, labels, formats). This clearly distinguishes it from sibling tools like get_castable_data or get_castable_info.

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?

Usage is implied by the descriptive name and the stated purpose, but there is no explicit guidance on when to use this tool versus alternatives such as list_compute_columns or get_castable_info. The error-behavior note is useful but does not address tool selection.

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