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

Annotations already cover read-only, idempotent, non-destructive and open-world traits, so the bar is lower; the description still adds real value by declaring that an UNMEASURED axis is a first-class published answer, 'never an error and never a zero,' which prevents an agent from treating a gap as failure. It also states it is 'never a certification,' a meaningful scope disclaimer. It does not mention auth, rate limits, or payload size.

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?

Identity and the no-argument rule are front-loaded, followed by the field enumeration and the unmeasured semantics. The long em-dash construction with the field list is dense but every clause carries information; the 'never a certification' disclaimer earns its place as a scope boundary.

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?

With zero parameters, an output schema present, and full annotation coverage, the description supplies everything needed: where the data lives (the board URL), what an unmeasured row means, and the non-certification caveat. The only gap is the absence of any pointer to sibling tools (get_axis, board_totals) that an agent might reasonably consider first.

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?

The tool takes zero parameters, which is the baseline-4 case. The description reinforces this by stating it takes no argument, exceeding what the empty schema communicates on its own.

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 names a specific resource (the custody-disclosure axis of the live GSPC board) and enumerates the fields it exposes (n, accuracy, interval, MEASURED/UNMEASURED status, family, kind, artifact URL, dates), which effectively identifies it as a single-axis read tool. The resource name distinguishes it from the many sibling axis_* tools. The odd phrasing 'this tool IS the axis' obscures the verb slightly, and it never mentions get_axis, the obvious generic sibling.

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?

'This tool IS the axis, so it takes no argument' tells the agent it can be called with empty input, and the unmeasured-axis clause gives interpretation guidance. But there is no explicit when-to-use rule and no routing versus alternatives such as get_axis, board_totals, or other axis_* tools. Usage is only implied by the resource identity.

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