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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral value beyond that: it explains what cvss_explain contains, instructs the agent never to guess values, and says to call once per CVE for multi-CVE requests. It does not discuss caching, rate limits, or behavior on unknown/invalid CVEs, which keeps it short of a 5.

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?

Content is front-loaded and clearly sectioned, but it is long for a one-parameter tool and repeats the schema in an 'Inputs' section and the output schema in an 'Outputs' section, neither of which earns its place. The illustrative CVSS vector example is useful but disproportionate.

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 annotations covering safety/idempotency and an output schema present, the description already does more than required: it lists returned fields, explains the one non-obvious field (cvss_explain), and gives usage guidance. An agent has everything needed to call it correctly and interpret the result.

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 there is a single required parameter, so the schema already documents cve_id fully. The description restates the same CVE-YYYY-NNNNN format without adding validation rules, error behavior, or format nuances beyond the schema. Baseline 3 applies.

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 verb+resource (get CVSS and current EPSS score for a specific CVE) and enumerates exactly what the risk snapshot contains. It also names the sibling that handles the adjacent case (epss_timeseries for historical trends), so an agent can differentiate without opening the schema.

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?

Provides an explicit 'When to use this tool' section with four concrete user phrasings, names the exclusion condition for EPSS historical trends, and routes to related tools (sightings_search, ssvc_calculator) for fuller assessments. Nothing about selection 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.