get_castable_data

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

No annotations are provided, so the description carries the full burden of disclosing behavior. It only says 'Fetch rows' without explicitly stating the operation is read-only or describing pagination behavior, error handling, or any side effects. This leaves gaps for a tool that should communicate its non-mutating nature.

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, front-loaded sentence with no redundant information. It is concise and directly states the core function, making it easy to read and understand.

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's low complexity, full parameter schema, and presence of an output schema, the description is largely complete. It could provide more context about when to use it relative to sibling read tools, but the essential information for invocation is covered by the schemas and the short description.

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 provides descriptions for all five parameters, and the tool description adds no additional parameter-specific semantics. Since schema coverage is 100%, a baseline score of 3 is appropriate; the description does not need to compensate for missing 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 clearly states the tool's function: fetching rows from a CAS table. It uses a specific verb ('Fetch') and identifies the resource, distinguishing it from siblings like get_castable_columns which retrieves column metadata. The phrase 'with column names' is slightly ambiguous but acceptable.

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 provides no explicit guidance on when to use this tool versus alternatives such as list_castables or get_castable_columns. Usage context is only implied by the name and description, and no when-not-to-use scenarios are mentioned.

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