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

With no annotations, the description carries the full burden and does substantial work: it discloses conditional payload sections (CISA SSVC decision points only 'when CISA published them', advisory context only 'when cve.now has read the vendor advisory') and even enumerates the four exposure values. It omits error/not-found behavior and any auth or rate-limit context, which keeps it from a 5.

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?

One sentence, front-loaded with the core action and resource, with the conditional return details trailing. The second half is dense with parentheticals but each clause describes a distinct part of the response, so little is wasted.

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?

There is no output schema, so the description must explain the return value, and it does: JSON entry, optional SSVC fields, optional advisory context with a defined exposure vocabulary. The main remaining gap is behavior on an unresolvable or unknown identifier.

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% with a single documented `id` property, so the schema already supplies the parameter's meaning and example. The description only restates the accepted identifier types, adding no format, normalization, or validation detail beyond the schema — baseline 3 applies.

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 and resource ('Get one vulnerability entry') and enumerates the three accepted identifier namespaces (CVE, GHSA, OSV), so the agent knows exactly what it retrieves. It does not distinguish itself from siblings such as `search`, which is the natural alternative for keyword-based lookups, so it stops short of a 5.

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: the 'by CVE, GHSA or OSV id' phrasing signals that this is an exact-identifier lookup rather than a search. There is no explicit statement of when to prefer this over `search` or `check_stack`, and no guidance on what to do when the ID is unknown.

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