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 valuable context beyond annotations: it specifies the data source (cveawg.mitre.org, CVE Program, MITRE Corporation), states 'no auth required', and clarifies the return format (CVE JSON 5.x). It doesn't describe pagination or error behavior, but for a single-record fetch with an output schema present, this is sufficient.

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 information-dense but compact: it covers the resource, format, content fields, sibling differentiation, an example, data source, and auth status in three sentences. Every sentence earns its place, and the most important information (what it fetches) is front-loaded.

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 single-parameter read-only tool with an output schema, the description is complete. It tells the agent what the tool returns, how it differs from the closest sibling, what data source it uses, and that no auth is required. The output schema covers return structure, and annotations cover safety. Nothing essential is missing.

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%, so the schema already documents the single parameter cve_id with an example. The description reinforces this by providing a concrete example ('CVE-2021-44228 (Log4Shell)') and explaining what the returned record contains. Since the schema does the heavy lifting and the description adds a real-world example, a 4 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 states a specific verb ('Fetch'), a precise resource ('full canonical CVE record as published by the assigning CNA'), and the exact format ('CVE JSON 5.x format'). It explicitly distinguishes itself from the sibling nvd.cves.detail by contrasting the authoritative source record with NIST's downstream-enriched copy. This is a textbook example of 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?

The description explicitly names the alternative tool (nvd.cves.detail) and explains the difference in data provenance and enrichment, giving an agent a clear decision rule: use this tool for the authoritative CNA record, use nvd.cves.detail for NIST's enriched copy. It also provides a concrete example (CVE-2021-44228) and states the data source and auth requirements.

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