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

With no annotations present, the description carries the full burden and does well: it declares 'Keyless, read-only' (no auth required, non-mutating) and enumerates the returned fields (vendor/product, added date, remediation due date, ransomware campaign usage). It stops short of describing failure behavior for a CVE that is absent from the catalogue.

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?

Three tight sentences, front-loaded with the core purpose, followed by return contents and the workflow hook. Every sentence earns its place with no padding.

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, and the description compensates by enumerating the returned fields, so an agent knows what comes back. Safety profile, auth posture and input meaning are all covered for a simple single-parameter lookup.

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?

There is one parameter and schema description coverage is 100%, so the schema already documents the CVE ID and its format. The description adds no extra syntax, casing or normalization guidance, so the 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?

Specific verb ('Check whether a CVE is in') plus a precisely named resource (CISA's Known Exploited Vulnerabilities catalogue), with the semantic meaning spelled out ('confirmed exploited in the wild, the strongest patch-this-now signal'). This cleanly separates it from siblings like cve_lookup, cve_triage and epss_score 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?

Gives clear context for when to reach for it: 'Interprets the CVE IDs host_exposure surfaces,' which ties it into an explicit upstream workflow. It does not, however, state exclusions or name alternatives such as cve_lookup or epss_score for non-KEV CVEs, so it falls short of a full when/when-not treatment.

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