Newly exploited vulnerabilities

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so safety is covered. The description adds behavioral details beyond annotations: newest-first ordering, optional filters, and the specific row fields returned (CVE, vendor, product, name, date added, federal due date, EPSS). This gives the agent a clear expectation of output shape and ordering without contradicting annotations.

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?

Two sentences with zero waste. The first sentence front-loads the core purpose and filters; the second lists output fields. Every word contributes to the agent's understanding. This is appropriately concise.

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?

Given the moderate complexity (4 optional parameters), existing output schema, and comprehensive annotations, the description covers the essential functional aspects: time window, filters, ordering, and output columns. No critical gaps for calling the tool correctly. Slight omissions like pagination or limit semantics are minor and covered by defaults.

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 compensate. It does: 'last N days' explains the days parameter, 'optionally only for a vendor or product' explains vendor_or_product with examples, and 'only ransomware-linked' explains ransomware_only. The limit parameter is not explicitly mentioned, but the default of 25 and the context of returning rows implies it. The examples (fortinet, chrome, exchange) add practical value.

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 states a specific action (retrieve CISA KEV additions) with a clear resource (the Known Exploited Vulnerabilities catalog) and time window (last N days). It distinguishes itself from siblings like package_vulns (package-specific) and vuln_details (details) by focusing on recent additions. The mention of filters and output fields further clarifies 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?

The description clearly implies usage for recent CISA KEV entries with optional filtering. It doesn't explicitly exclude alternatives or name sibling tools, but the context makes it obvious this is for time-based catalog queries, not package or prioritization tasks. This is clear context without exclusions.

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