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

With no annotations provided, the description carries the full burden, and it excels: it discloses 'Public read (no auth),' explains the analytical method (Spearman rho, repeat-offender split), and includes a clear limitation ('95% cap: this is product-level stickiness...'). This goes well beyond minimal requirements and is genuinely transparent.

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 longer than a simple two-sentence blurb, but every sentence delivers value: trigger, question, methodology, finding, caveat, and usage. It is front-loaded with the most important usage cue. Slight redundancy exists between the rhetorical question and the 'Answers...' sentence, but overall it is well-structured and not bloated.

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?

Despite having no output schema and no annotations, the description tells the user enough to invoke and interpret the tool: what it analyzes, how it works, what the key finding is, what the limitations are, and how to pass parameters. It also covers auth requirements. For a read-only analytical tool, this is complete.

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 schema already documents the single 'days' parameter completely (type, range, default, and description). The description repeats this information ('Pass {"days": N} for the recent window (30-720, default 180)') but does not add new semantic meaning beyond what the schema provides. Baseline 3 is appropriate given full 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 tool's purpose: analyzing CISA KEV to determine whether exploitation risk sticks to proven products or spreads to new ones. It uses specific verbs like 'Analyzes' and 'Answers' and specifies the resource and methodology. However, it does not explicitly distinguish itself from sibling tools such as kev-vendor-risk, so it stops short of a full 5.

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 first line gives an explicit trigger: 'CALL when the user is prioritizing patching or asks whether a product's exploitation risk is chronic vs a one-off.' This provides clear context for when to use the tool. It does not mention when not to use it or name alternative tools, but the guidance is strong enough for a 4.

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