nvd_cve_lookup

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

With no annotations provided, the description carries the burden of behavioral disclosure. It adds useful runtime context by explaining the optional NVD_API_KEY environment variable and the rate limit difference (50 req/30s vs 5). It also describes the returned content in enough detail to convey that this is a read-only lookup.

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 with no filler. It front-loads the core purpose and return value, then adds the rate-limit and API-key context, with every sentence providing actionable information.

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 lookup with no output schema, the description is largely complete: it states the resource, the key returned fields, and a critical rate-limit detail. It could be slightly more precise about the exact response format or error behavior, but nothing essential is missing for an agent to select and invoke the tool 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 input schema already documents the single parameter with a clear example (CVE-2024-3400), so schema coverage is 100%. The description does not add significant extra parameter semantics beyond reinforcing that the input is a CVE identifier, which meets the baseline for high schema coverage.

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 the specific action ('Look up a CVE') and the exact resource ('NIST National Vulnerability Database (NVD)'), and it enumerates the returned fields (CVSS v3/v4, CPEs, CWE, references, dates). This makes it easy to distinguish from sibling tools like epss_bulk_check or check_cisa_kev, even without explicitly naming them.

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 when to use the tool: when a full NVD CVE record is needed. It gives a clear context by listing what the record contains, but it does not explicitly state when not to use it or mention alternatives for related lookups such as EPSS scores or CISA KEV status.

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