set_detail_rows

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

With no annotations, the description carries the full burden for behavioral disclosure. It explains the two modes and gives an example DAX expression, which is helpful. But it does not disclose potential side effects (e.g., overwriting existing detail row definitions), validation of the DAX expression, or whether the change is immediate or transactional. The core behavior is clear, but edge-case behavior is undocumented.

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, front-loaded with the main purpose, and every clause contributes meaning. The example is illustrative without being verbose. There is no redundant or filler content.

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 description covers the core operation and parameter semantics but omits important contextual details: the meaning of sessionId is not explained, and there are no caveats about validation, reversibility, or interaction with existing drillthrough settings. Given the tool has no annotations and no output schema, a slightly more thorough description would be expected, though the current text is not 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?

Schema description coverage is 75%, so the baseline is 3. The description adds semantic value beyond the schema by explaining that a null measure sets the table default, and by providing an example DAX expression for daxTableExpression. It does not mention sessionId, but that parameter appears to follow standard session conventions and is not critical to understanding the tool's operation.

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's purpose with a specific verb ('Define drillthrough detail rows') and clearly explains the resource (DAX table returned on drillthrough). It distinguishes between per-measure and table-default modes, effectively differentiating from the sibling set_table_detail_rows by covering both use cases. The purpose is unambiguous.

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 explicit instructions for when to include a measure (per-measure definition) versus omit it (table default). This gives clear context for the primary decision an agent must make. However, it does not explicitly mention alternative tools like set_table_detail_rows or state when to prefer this tool over that sibling, so exclusions are missing but not misleading.

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