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

Annotations already declare readOnly/idempotent/openWorld, but the description adds what the annotations cannot: a hard cap of 20 items, the exact fields returned, the fact that licence/CVE designation/NVD notice appear once, and — most valuable — that each call consumes one request of the monthly quota. Missing only failure behaviour (e.g. quota exhaustion or what happens past 20).

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: what it returns and its ordering first, then the follow-up route, then the cost. Every sentence carries distinct decision-relevant information with no filler.

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 no output schema, the description compensates by enumerating the returned fields, and it discloses the quota cost for a billed, open-world tool. It does not explain how an agent would reach older CVEs beyond the 20-item window, which is the one remaining gap for a capped listing.

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%, with both limit (default, max 20) and severity enum fully documented in the schema. The description only restates the severity filter and the 20-item ceiling and adds no format or edge-case guidance beyond that, 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?

States a specific verb+resource ('most recently published CVEs'), the ordering ('newest first'), and the optional filter. It is clearly separable from get_cve (which it names) and from list-oriented siblings like exploited_cves by virtue of the 'most recently published' scope.

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?

Explicitly routes the agent onward: 'Follow up with get_cve for EPSS, KEV, exploitation evidence, affected packages and advisories,' which draws the boundary between this light listing and the detail tool. It does not state when to prefer the sibling exploited_cves instead, nor any when-not condition, so it stops short of full routing.

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