CISA KEV check

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

Annotations already declare readOnly, idempotent, open-world, non-destructive, so the safety profile needs no restating. The description adds real interpretive value with the caveat that a product match means the product has been exploited historically, not that the queried version is affected. It stops short of describing what a miss/empty result means or how results are shaped.

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 with the core action front-loaded, followed by the interpretive caveat, then the routing advice. No filler and no repetition of the title.

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?

Purpose and usage are complete, but with no output schema the description never indicates what comes back (KEV entry fields? booleans per input? matches only?), and investigation_id is left unexplained for a tool that otherwise demands careful interpretation. Adequate for routing, thin for correct invocation.

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 0%, so the description must carry the parameter burden, and it only partially does: it names CVE IDs and product names as the accepted inputs but gives no format guidance (e.g. CVE-YYYY-NNNN) or array/optionality behavior. The third parameter, investigation_id, is never mentioned anywhere, leaving it entirely opaque.

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 ("Check") and resource (CISA's Known Exploited Vulnerabilities catalog) plus accepted inputs (CVE IDs and/or product names). It also differentiates itself from siblings by noting version checks and CVE lookups already return KEV status for their CVEs.

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 explicit routing: use version checks / CVE lookups first because they already surface KEV status, then use this "once per product for its KEV history, or for CVE IDs from elsewhere." It also states a when-not-to-over-read rule for product matches, so the agent knows what conclusions the result does and does not support.

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