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

Annotations already cover read-only and idempotent, so the bar is lower, but the description goes further: it discloses that results are truncated by default (no CPE matches, max 20 references with exploits and patches prioritized, 10 newest advisories) and that a 'trimmed' indicator reports what was removed. This is exactly the kind of non-obvious output-shaping behavior an agent needs before deciding whether to set full=true.

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 no filler; the truncation default and the trimmed indicator are front-loaded before the parameter note. The opening fragment lacks a verb, which slightly hurts immediate parseability but costs no padding.

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 two-parameter read-only lookup with no output schema, the description covers the lookup keys, alias handling, merged-id resolution, default truncation, and the trimmed metadata field. Remaining gaps (error behavior for unknown ids, exact structure of the trimmed field) are minor.

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%, so baseline is 3, and the description earns an extra point by explaining the default state of the optional full parameter (shortened record) and what 'full' restores, plus the accepted alias forms for id. It adds semantics about the default that the schema only implies.

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 identifies the resource precisely (a vulnerability record retrievable by Threatist id or by an alias like CVE/GHSA) and explains the merged-id case. It is a noun phrase rather than a verb, but the resource and lookup key are unambiguous enough to distinguish it from siblings like search_vulnerabilities or get_advisory.

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?

Usage is only implied: an agent can infer this is the direct-lookup tool versus a search tool, but the description never states when to prefer it over search_vulnerabilities, list_exploited, or get_advisory. The only explicit when-condition is the indirect hint that the default is trimmed unless full detail is needed.

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