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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description usefully adds the OSV.dev dependency and the scope of what is checked (vulnerabilities, deprecation, latest version), but it never discloses that results may be masked unless a paid key/signature is supplied — a material behavioral trait relegated to the parameter descriptions.

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?

Two sentences, zero filler, front-loaded with the core identity and then the data source and coverage. Nothing is repeated from the title or schema.

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?

With no output schema, the description does supply the return scope (vulnerabilities, deprecation status, latest stable version), which is the main thing an agent needs. It stops short of explaining result masking / paid-unlock behavior, so a small but real gap remains for a tool with payment-gated output.

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 name, version, ecosystem, and the two payment parameters are fully documented in the schema itself. The description only restates the ecosystem set already enumerated in the schema and adds no syntax or default nuance beyond it, making the baseline 3 appropriate.

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 — scanning npm/PyPI/crates.io packages for CVEs — and names the backing data source (Google OSV.dev). The combination of 'package' scope plus the declared ecosystems separates it cleanly from the broader security_audit sibling without needing to open either schema.

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 phrase 'for coding agents' implies a usage context, and the listed ecosystems imply what can be audited, but there is no explicit when-to-use versus when-not, nor any pointer to alternatives like security_audit or compliance_check. Usage is inferable rather than stated.

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