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

With no annotations, the description carries the full burden and does so: it discloses payment mechanics ($0.01 x402 in params._meta, PAYMENT-SIGNATURE header, or Gumroad X-API-KEY), the NVD keyword-search accuracy caveat, and the 50-result cap. These are exactly the non-obvious traits an agent needs before invoking.

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?

Front-loads purpose, then labeled sections for differentiation, exclusions, and behavior. Every sentence is substantive, though the payment/auth detail is dense and slightly long relative to the rest.

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?

No output schema exists, but the description explains the return contents (CVSS, EPSS, CISA KEV status, sorted by exploitation risk, max 50), the auth requirements, and the accuracy limits. Nothing needed to call it correctly 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 vendor, product, version, and only_kev are already documented in the schema; baseline is 3. The description adds only that version filtering is optional and that results are enriched/sorted, without new semantics for any individual parameter.

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 ('returns CVEs affecting a given vendor/product') plus the enrichment and ordering. It explicitly differentiates from get_cve_details and get_cve_batch by CVE-id vs vendor/product discovery, so an agent can route without opening any 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?

Contains explicit SIBLING DIFFERENTIATION and USAGE EXCLUSIONS sections: use when you lack an exact CVE id, do not use for a known CVE id, and be aware results are NVD keyword search near-matches rather than strict CPE matches. That is textbook when/when-not guidance.

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