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

Annotations already declare safety traits such as idempotentHint=true and destructiveHint=false. The description adds important behavioral context beyond annotations: it requires payment via x402 / X-Bazaar-Key at 0.01 USDC and returns a score plus severity rating. It does not explain payment failure behavior, but it covers the key auth cost detail that an agent needs.

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 tightly written sentence with the paid-access note front-loaded and the computational purpose clearly stated. There is no redundant or filler text.

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 simple one-parameter calculator with full schema coverage and no output schema, the description is largely complete: it names the input, the exact score range, the severity rating output, and the paid access requirement. It could be stronger if it briefly clarified malformed-vector or payment-error behavior, but it is adequate.

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% for the single 'vector' parameter, so the schema already carries the parameter documentation burden. The description names the input type but adds no syntax example, validation rules, or format guidance beyond what the schema provides.

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 ('Compute'), a specific resource ('CVSS v3.1 Base Score'), and the exact output scope ('0.0-10.0 and severity rating'). It is clearly distinguishable from the many lint/calc siblings because the CVSS v3.1 domain is explicit.

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 implies the tool is used when a CVSS v3.1 vector string is available, and it notes the paid x402 requirement. However, it does not explicitly frame when to use this tool versus any alternative, nor does it state exclusions or prerequisites beyond the payment header.

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