preview_query

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

Annotations already declare readOnlyHint=true, which covers the safety profile. The description adds the constraint 'open Excel workbook only,' which is a useful behavioral note. However, it doesn't disclose what happens when the workbook is not open or other edge cases, so it adds limited value beyond the annotations.

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 sentences long, directly stating the core function and a usage tip. It is front-loaded with the primary purpose and contains no filler or redundant information, making it highly concise and well-structured.

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 that there are 3 parameters with zero schema descriptions and no output schema, the description is insufficient. It does not explain parameter semantics, the meaning of 'rows,' or the return format beyond 'column names and first rows.' While it notes the workbook constraint, it lacks critical details needed for an agent to call the tool correctly without additional context.

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 0%, and the description does not explain any of the three parameters (source, name, rows). It doesn't clarify what 'source' and 'name' refer to, nor does it mention the 'rows' parameter with its default of 20. The description fails to compensate for the lack of schema documentation, leaving the agent to infer parameter meanings.

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 returns column names and first rows of a query, and specifies the context of an open Excel workbook. It also mentions a concrete use case ('before apply_transform'), which helps identify the tool's purpose. However, it does not explicitly distinguish it from sibling tools beyond that use case.

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 gives a clear usage direction: 'Use it to get real column names before apply_transform.' This provides a specific scenario for when to invoke the tool, though it doesn't mention when not to use it or compare it to alternatives.

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