get_castable_info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, covering the safety profile. The description adds the types of metadata returned (row count, column count, size), which slightly extends beyond the annotations. However, it doesn't describe error behavior, permissions, or other edge cases; given annotations handle safety, a 3 is appropriate.

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, well-front-loaded sentence with no filler. It efficiently states what the tool does and gives examples of returned metadata. Zero wasted 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?

The tool has a simple signature (3 required parameters), good annotations, and an output schema that presumably details the metadata fields. The description sufficiently conveys the return concept (row count, column count, size) without over-explaining. It doesn't mention prerequisites or error cases, but for this low-complexity read operation, it's largely complete.

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?

Schema description coverage is 100%, so each parameter is already documented in the input schema. The description does not add any extra semantics beyond what the schema provides (e.g., it doesn't hint at how parameters are used). Per rubric, baseline 3 applies when schema does the heavy lifting.

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 uses a specific verb ('Get metadata') and a clear resource ('a CAS table'), listing concrete examples (row count, column count, size). It clearly distinguishes from siblings like list_castables (lists tables) and get_castable_columns (gets columns) by focusing on table-level metadata.

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 implies usage: it's for a single named table, not for listing. It doesn't explicitly say when not to use it or name alternatives, but the context is clear from the wording. No exclusions are stated, but that's acceptable for a straightforward read tool.

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