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

No annotations are provided, so the description carries the full behavioral burden, and it does not disclose that this is a read-only external lookup, what the result contains, or any rate limits/latency. The only useful behavioral hint (version omission) lives in the schema, not the description.

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 one-liner is brief but not appropriately sized; it under-specifies a three-parameter tool rather than being efficiently concise. There is no front-loaded detail beyond the bare name-plus-source.

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 annotations, no output schema, low schema coverage, and two undocumented required parameters, the definition is too thin for an agent to invoke correctly. It should at minimum explain ecosystem values, required inputs, and what the check returns.

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 only 33%: only 'version' has a description, while the required 'ecosystem' and 'package' parameters are undocumented. The description adds nothing about parameter meaning — notably it never states valid ecosystem values (npm, PyPI, etc.) or that ecosystem/package are mandatory, so it fails to compensate for the coverage gap.

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 the resource (package vulnerabilities) and the backing service (OSV.dev), so the purpose is identifiable, but it's a noun phrase rather than a full statement of what the check does or returns. It gives no differentiation from related siblings such as typosquat_check, repo_health_check, or security_scan.

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?

There is no indication of when to use this tool versus alternatives, nor any prerequisites (e.g., that ecosystem and package are required, or what ecosystems are accepted). The agent must infer usage entirely from the name and schema.

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