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

With no annotations, the description carries the burden of disclosing behavior. It communicates a read-only external lookup against OSV.dev and lists aggregated sources and supported ecosystems, which is enough to infer non-mutating behavior. It does not mention rate limits or failure behavior, but these are lower risk for a simple advisory lookup.

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 three focused sentences with no filler. The main purpose is front-loaded, the source list is compact and useful, and the use-case sentence adds practical value without 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 straightforward lookup, the description covers the data source, supported ecosystems, version semantics, and intended use case. There is no output schema, and return structure is not detailed, but 'known CVEs/advisories' gives an agent enough expectation about the result.

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 100%, so the schema already documents name, version, and ecosystem. The description reinforces that a version is optional/pinned and lists ecosystems, but it does not add meaning materially beyond the schema.

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 a specific verb ('Look up'), a specific resource (a package against OSV.dev's aggregated vulnerability database), and the outcome (known CVEs/advisories). This clearly distinguishes it from siblings like safe_browsing_check or security_headers_audit, which focus on different security concerns.

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 gives concrete usage context with 'Useful before adding a dependency,' making it clear when an agent should consider this tool. It does not explicitly name alternatives or state when not to use it, but no sibling appears to be a direct package-vulnerability alternative.

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