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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds that the data is free USGS/public, which is useful provenance context, but does not disclose update frequency, freshness, geographic scope, or rate limits. With annotations carrying the behavior load, this is adequate but not rich.

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 a single efficient sentence that front-loads the tool's domain and then enumerates the three signal dimensions. No filler or repetition. It could be slightly clearer with a verb, but it earns its place.

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?

For a read-only, single-parameter, no-output-schema tool, the description gives the essential domain and dimensions. However, it omits what the output shape is (numeric concentration, categorical reliance?), any limitations (coverage of minerals, time lag), and when to prefer it over other signals. With annotations covering safety and schema covering the parameter, this is minimally sufficient but leaves gaps an agent might need for confident use.

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?

Schema coverage is 100% with a single documented parameter that includes examples (lithium, cobalt, gallium). The description does not expand on parameter meaning beyond the schema, but with full schema coverage and one simple string parameter, the baseline of 3 is appropriate.

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 specifies the verb-less signal but clearly identifies the resource: 'critical-minerals supply signal for a commodity' and lists the dimensions returned (supply concentration, import reliance, refined vs mined read). It distinguishes the tool from the thematic siblings (equity_signal, labor_pulse, smart_money, token_scan, wallet_pnl) via the commodity domain, but does not explicitly name a contrasting alternative. This is clear but stops short of full sibling differentiation.

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?

No when-to-use or when-not-to-use guidance is provided. The description mentions it is free USGS/public data, which implies it is a reference signal, but it does not advise when an agent should call this instead of other market or supply tools. The sibling tools are from unrelated domains, so context is inferable but not explicit.

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