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

Beyond the readOnlyHint/openWorldHint annotations, it discloses that results are computed live, enumerates what is returned (rho, repeat-offender vs first-time split, concentration share, an `interpretation` sentence), states it is a public no-auth read, and adds an honest caveat that this is a proxy for exploitation dynamics rather than proof of exploit timing.

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-loaded with the core purpose and use case, and the rhetorical 'STICK vs SPREAD' framing efficiently conveys the analysis. There is mild redundancy between the opening 'for patch prioritization' and the later 'how should I prioritize patching' question, plus a duplicated mention of the 30-720 window.

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 describing the returned metrics and interpretation field, states the auth model, the default window, and the interpretive limits of the result. An agent has everything needed to decide to call it and to read its answer.

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 coverage is 100% and the single `days` parameter already documents range and default, so the description adds no meaning beyond it — it simply restates '30-720, default 180'. Baseline 3 applies when the schema does the work.

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 analytical verb and resource: it measures whether product-level exploitation risk is chronic or one-off by correlating CISA KEV historical counts against recent additions via Spearman rho. The explicit 'product-level' framing also separates it from the sibling kev-vendor-risk, which operates at vendor level.

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 frames the decision context clearly ('how should I prioritize patching — chase the chronic offenders, or watch for newcomers?') and names the intended use for patch prioritization. It stops short of explicitly saying when NOT to use it or naming kev-vendor-risk as the alternative for vendor-level questions.

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