package_vulns

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

Annotations already declare readOnlyHint and openWorldHint. The description adds valuable context beyond this: the data source (OSV.dev), version scoping behavior, and the note that it is free (no payment required). It does not contradict any annotations and covers the key behavioral aspects for a read-only enumeration tool.

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 two sentences, front-loaded with the primary purpose, then clarifies the key behavioral nuance (version scoping), and ends with a useful cost-related note. Every sentence earns its place; no filler or 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 simple read-only list tool, the description covers the essential aspects: purpose, source, version behavior, and cost. It doesn't describe the return format, but with no output schema and a clear 'list' verb, this is a minor gap. The description is complete enough for an agent to select and invoke the tool correctly.

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 the schema already describes all three parameters. The description adds meaningful semantics for the version parameter by explaining the difference between passing a version (scope to that version) and omitting it (see all advisories). This goes beyond the schema's minimal description.

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') with a clear resource ('known vulnerabilities') and explicitly specifies supported ecosystems (npm, PyPI, crates.io). It distinguishes itself from sibling tools like package_snapshot, package_deps, and package_downloads by focusing on vulnerabilities.

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 clear context: use this tool to check security vulnerabilities for a package. It explains the optional version parameter and the behavior when omitted, providing practical usage guidance. It doesn't explicitly mention alternatives or exclusions, but the purpose is so distinct that the usage context is clear.

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