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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it discloses what is returned (field names, on-chain provenance UIDs, paid REST endpoint) and that the full data is free but rate-limited via a separate GET path.

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 purpose is front-loaded in the first sentence and the operational details follow logically. The enumeration of all 20 minerals duplicates the schema enum, adding some length without new information, but the overall structure is efficient and readable.

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 return-value documentation is not required, and the annotations cover the safety and idempotency profile. The description supplies the extra context an agent needs (preview vs. full data, provenance UIDs, downstream compliance uses), leaving only sibling differentiation as a minor gap.

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?

There is one required parameter with 100% schema description coverage and an exhaustive enum, so the schema already carries the semantics. The description merely repeats the mineral list rather than adding slug syntax or format guidance, which fits the baseline 3 for a fully documented single parameter.

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?

States a specific resource (USGS Mineral Commodity Summaries benchmark data) and characterizes itself as a 'discovery preview' returning field names, provenance UIDs, and endpoint info. It is clearly distinguishable from data-fetching siblings, though it never names benchmark.sample or benchmark.runs to differentiate the preview from the full retrieval.

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?

It gives downstream use cases (due diligence, UFLPA, EU Battery Regulation, CBAM/CSDDD) and notes the full data is available free via GET /api/benchmark/{commodity}, which implies this is a metadata-preview step. However, it never says when to prefer this over the sibling benchmark.sample/benchmark.runs tools, so sibling routing is left to inference.

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