add_subtotal_column

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

The description explains the structural changes made (TablixMember, TablixColumn, cells) and the aggregates parameter. Since no annotations are provided, the description carries the full burden. It does not cover error conditions, destructive nature (e.g., if a subtotal already exists), or permissions, which would be helpful for a mutation tool.

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 concise at 4 sentences, well-structured, and front-loaded with the core purpose. Every sentence adds necessary information without 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?

Given moderate complexity (6 params) and no output schema, the description explains the input well. However, it does not mention whether this tool requires an editing transaction (sibling tools include transaction management), nor does it describe the return value or confirmation of success. This is a notable gap.

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%, so the description must add all parameter meaning. It explains all 6 parameters: path, tablix_name, group_name, aggregates (as a list of {row, expression} with 0-based row index), width (default '1in'), and position ('after' or 'before'). This adds significant value beyond the schema.

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 is a 'column-axis mirror of add_subtotal_row' and precisely describes its function: adding a TablixMember, TablixColumn, and cells. It distinguishes from the sibling tool add_subtotal_row and explains the parameters, making the purpose very clear.

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 includes a prerequisite ('Group must have been added via add_column_group') and explains the 'position' parameter with default behavior. However, it does not provide explicit guidance on when to use this tool versus alternatives like add_static_column, nor does it mention any exclusion scenarios. The mention of add_subtotal_row as a mirror provides some context.

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