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

Annotations already declare readOnlyHint=true and non-destructive, but the description adds important behavioral context: the $0.50 USDC payment requirement and the use of x402 on Base. It also describes the return structure. No contradictions with annotations. It doesn't cover error handling or rate limits, but the added payment and endpoint details merit a 4.

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 three sentences long, each earning its place: purpose and outputs, target users, and payment/endpoint. It is front-loaded with the core functionality. Slightly long for a simple tool, but the complexity of the outputs justifies the length.

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?

With an output schema present, the description sufficiently covers the tool's purpose, outputs, use case, and payment requirement. It lacks potential edge-case details (e.g., partial data behavior) but overall provides a complete picture for an agent to invoke it correctly.

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 schema provides 100% coverage with a full enum for 'commodity' and a clear description ('Mineral commodity slug.'). The tool description adds only general context (e.g., '20 critical minerals') but no additional parameter semantics. Baseline 3 is appropriate because the schema already carries the weight.

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 states a specific verb and resource: 'Supply chain resilience score + scenario analysis for 20 critical minerals.' It enumerates concrete outputs (0-100 score, vulnerability level, 5-factor breakdown, 3 scenario tests) that clearly distinguish it from siblings like supply_share and stockpile_level. The intended audience (procurement agents, supply-chain strategists) further clarifies its purpose.

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 provides clear context: 'Procurement agents and supply-chain strategists use this for vulnerability triage.' This implies the tool is for resilience assessment rather than raw data lookup. However, it does not explicitly mention alternatives or exclusions, so it stops short of a 5.

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