vdb_lookup

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

With no annotations, the description carries the full burden. It states it fetches a single vulnerability, implying a read-only operation, but discloses nothing about behavior on not-found, error handling, authentication requirements, or the response structure. It is minimal and does not go beyond the basic action.

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 single, efficient sentence that front-loads the action and resource, and immediately clarifies acceptable input formats. There is no wasted text; every word adds value.

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?

The tool is simple (one parameter, no output schema), but the description does not explain what the response looks like (e.g., full record, metadata) or how errors are handled. While not complex, it leaves some ambiguity about the return value, making a 3 appropriate.

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 only defines 'id' as a string with no description. The tool description compensates by explaining that the id can be a CVE, GHSA, or VDB-SLOP identifier, giving examples. This adds meaning beyond the raw schema, though the VDB-SLOP format is truncated with an ellipsis, leaving some ambiguity.

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 'Fetch' and names the resource 'a single vulnerability', explicitly stating it works by ID or alias with concrete examples (CVE, GHSA, VDB-SLOP). This clearly distinguishes it from siblings like vdb_search or vdb_check_package, which are for broader searches or package checks.

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 implies usage when you have a specific identifier, but it does not explicitly contrast with alternatives or state when not to use it. It lacks explicit 'use this instead of X when...' guidance, though the intent is inferable from the tool name and the examples.

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