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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds behaviorally meaningful context beyond annotations: that timings include representative current-generation numbers rather than historical records, that results include source URLs, and that the data is sourced through a join on hardwareType. This adds useful caveats not captured in the annotations.

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 compact at three sentences, front-loaded with the output content and its units. Every sentence provides necessary detail: what is returned, how it relates to sibling tools, and a caution about the representative nature. It could be slightly tighter, but it is not verbose.

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?

Without an output schema, the description reasonably covers return fields: 2Q gate time, readout time, SI seconds, representative device, native 2Q gate name, and source URLs. It also explains provenance and intended use. Minor gaps remain, such as not describing what a typical response entry looks like or edge cases for missing timings, but overall it is adequately complete for the tool's purpose.

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 has zero parameters, so the schema leaves no semantics to clarify. Per rubric this is a baseline 4: the description cannot add parameter meaning if there are none, and it does not need to compensate since the tool takes no input.

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 uses a specific verb ('Return') and clearly states the resource: per-platform gate-cycle timings including exact fields (2Q gate time, readout time, device, gate name, source URLs). It differentiates itself from siblings by explaining the join with list_current_quantum_computers and explicitly targeting compute_quantum_volume_rate as a downstream consumer.

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 usage context: 'Use for runtime estimates, ratio analysis, or as inputs to compute_quantum_volume_rate.' It implies when to use this tool but does not explicitly state when not to use it or mention a specific alternative tool, so it misses the full when/when-not structure for a 5.

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