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

Annotations already declare the tool read-only and non-destructive. The description adds valuable behavioral context beyond annotations by disclosing the $0.02 per-call payment requirement and explaining that unpaid calls return the exact x402 payment terms. That is important pre-invocation information not present in the structured metadata.

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 short, front-loads the critical payment warning, and explains the output regime in one clear clause. The only minor flaw is redundancy between the title's payment note and the first sentence, but overall it is tight and scannable.

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 tool with a single parameter and no output schema, the description provides enough context to call it correctly: it names the input, specifies the output scale (low/med/high), defines the baseline window, and discloses payment behavior. It could include a concrete response example, but the simple domain makes that less critical.

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 description coverage is 100% and the single asset parameter is already documented with an enum and field description. The description adds little beyond calling the asset 'major,' so the schema carries the semantic weight; a baseline score 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 clearly states that the tool returns a volatility/drawdown risk regime (low/med/high) relative to a 30-day baseline for a supported crypto asset. It is more specific than a tautology and the title reinforces the paid nature, but it does not explicitly differentiate itself from similarly named siblings like crypto_regime, regime, or token_risk.

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 guidance on when to use this tool versus the sibling tools. It only explains payment behavior and the unpaid fallback, not the intended use case or conditions under which an agent should prefer this tool over alternatives.

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