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

Annotations already declare readOnly/idempotent/non-destructive, so the burden is light, but the description adds genuine semantics beyond them: an unmeasured axis is a first-class declared slot, never an error and never a zero. That is exactly the kind of behavior an agent would otherwise mis-handle (treating empty data as failure). The 'never a certification' disclaimer further sets expectations on the payload's authority.

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?

One front-loaded sentence establishes the resource and the no-argument contract, followed by the field list and then the unmeasured semantics. The field enumeration is dense but every clause carries information; nothing is padded.

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 description need not explain return shape, and it covers the one behavioral edge case (declared-but-unmeasured) that a schema cannot express. The remaining gap — how this axis relates to the get_axis sibling — is the only thing an agent is left guessing about.

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 the tool IS the axis and takes no argument, which prevents an agent from inventing filter parameters such as an axis name.

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 the specific resource — the detector-interop axis of the live GSPC board at a concrete URL — and enumerates the row contents (n, accuracy, interval, status, family, kind, artifact URL, dates), so an agent knows exactly what comes back. It lacks an explicit verb and never distinguishes itself from the sibling get_axis, so a reader must infer whether this is a fetch of one axis vs. a generic axis getter.

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?

There is no statement of when to call this versus get_axis, axis_interop-conformance, or measurement_index, all of which sit in the sibling list and plausibly overlap. The only usage-shaped information is the negative constraint 'takes no argument', which tells the agent nothing about selection.

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