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

Annotations already cover read-only/idempotent/non-destructive, so the bar is lower. The description adds real behavioral context beyond them: unmeasured slots are first-class and published rather than raised as errors, values are never zero-filled, and the result is explicitly 'never a certification'. What is missing is any note on whether output is a snapshot or live-refreshed.

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 URL are front-loaded and the field enumeration is compressed into one list; the em-dash clause carries the important unmeasured-is-not-an-error rule. Slightly dense and comma-chained, but nothing is wasted.

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?

An output schema exists, so the enumerated return fields are somewhat redundant and the description needn't explain return shape. The more important gap is relational: among ~30 sibling axis tools plus `get_axis`, the description does not establish why an agent should pick this one directly rather than through the generic axis accessor.

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?

Zero parameters, so the baseline is 4. The description reinforces this by stating explicitly 'this tool IS the axis, so it takes no argument', which removes any doubt an agent might have about needing to pass an axis identifier.

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?

Names a specific resource (the distribution-integrity axis of the live GSPC board), gives its base URL, and enumerates the returned fields (n, accuracy, interval, MEASURED/UNMEASURED, family, kind, artifact URL, dates). It is clear what an agent gets back, though the distinction from the sibling `get_axis` tool is left implicit.

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?

States the tool takes no argument and that an unmeasured axis is a valid answer, which is useful invocation context. However, it never says when to call this axis tool versus `get_axis`, `board_totals`, or `measurement_index`, and no alternatives or exclusions are named.

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