Convert output column to input

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

Annotations already declare destructiveHint=true and idempotentHint=false; the description adds genuinely new context: the operation is not undoable, values move with the column, and a 409 `dataset_in_use` is returned while a fill is running. That error-condition disclosure is valuable beyond the annotations, though the resulting state after conversion is only loosely described.

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 verb+resource leads, consequences follow, and failure mode is last — good front-loading. The opening line duplicates the title verbatim, which is a small redundancy but not costly.

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?

For a destructive, non-idempotent two-parameter mutation with no output schema, the description covers reversibility, data movement, and the key error case. What's missing is any hint of the returned representation or whether the previous input columns are affected.

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 coverage is 100%, so both `id` and `column` are already documented. The description reinforces that `column` must be the name of an existing filled output column and that the promoted column keeps the same name, which is modest added meaning over the schema baseline.

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?

States a specific verb and resource ('convert output column to input') and names the exact object affected ('`column`'). No sibling tool does anything comparable, so an agent can identify it uniquely without opening the schema.

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 rationale ('so later columns and dedupe can key on it') implies when this is useful, and the 409 condition signals when it will fail. But there is no explicit guidance on when to choose this over, e.g., rebuilding the dataset via build_dataset, nor any stated preconditions about the fill having completed.

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