Add column

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

With no annotations provided, the description carries the full burden. It discloses several key behaviors: appending after the last column, optional default-value filling, refusal on duplicate names, and file backup before writing. These details give the agent a clear understanding of side effects and failure conditions.

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 three sentences long, front-loaded with the primary action, and every sentence contributes unique information. There is no redundancy or filler, 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?

This is a simple tool with only two parameters and no output schema. The description covers purpose, behavioral rules, failure modes, and the relationship to sibling tools, making it fully self-contained and sufficient for correct use.

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 a baseline of 3 is appropriate. However, the description adds meaning beyond schema by explaining that default_value is written into every existing job row and that name uniqueness is enforced. This enriches the parameter semantics.

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 'Add a new custom column to the spreadsheet, appended after the last column' with a specific verb and resource. It distinguishes from sibling job tools by explicitly noting that job tools only handle standard columns and custom columns are managed with these column tools.

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 clear context about when to use this tool: for managing custom columns, as opposed to the built-in job tools which read/write standard columns. It also notes duplicate-name refusal, implicitly suggesting that a different tool (like modify_column) would be needed for existing columns, though it doesn't name the alternative explicitly.

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