list_kev_entries

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds meaningful context about how UUIDs identify KEV catalogs and that the base URL can be overridden via an environment variable. No contradictions with 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?

The description is a compact paragraph of four sentences. It front-loads the core purpose, follows with use cases, then gives essential UUID context and configuration details. Every sentence contributes necessary information with no redundancy.

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?

For a tool with 9 optional parameters, an output schema, and a clear domain, the description covers all necessary operational context: what it does, when to use it, how to identify catalog UUIDs, known examples, and configurability. The existence of an output schema covers return value details, so nothing critical is missing.

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%, providing baseline 3. The description adds significant semantic value by explaining the 'vulnerability_lookup_origin' parameter in depth, listing known catalog UUIDs and repeating the pointer to list_gcve_references. This enriches the schema's terse description of that parameter.

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 uses a specific verb ('List and filter') paired with a clear resource ('Known Exploited Vulnerability (KEV) entries'). It further clarifies the scope with concrete use cases: browsing catalogs, checking for a specific vulnerability, and finding recent entries. This clearly differentiates it from sibling tools like list_gna_entries.

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 explicitly states when to use this tool ('Use this tool to browse... check... find...') and points to a specific alternative for discovering KEV catalogs ('Use the list_gcve_references tool to discover available KEV catalogs and their UUIDs'). It lacks an explicit 'when not to use' statement, but the guidance is otherwise clear.

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