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

Annotations already provide readOnlyHint, idlempotentHint, and non-destructive semantics, so the description doesn't need to restate safety. It adds real behavioral context by specifying exact output fields, naming OSV.dev as the vulnerability source, noting sources for advisories, and stating the paid pricing model. No contradiction with annotations.

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 short sentences with the core data scope front-loaded and only the pricing note at the end. Every sentence carries needed information; there is no filler.

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 single-parameter tool with no output schema, the description gives a clear picture of returned data and benefits from safe annotations. However, it omits parameter format, requiredness, and selection criteria, leaving a significiant gap in practical usability.

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 0% and the only parameter 'paquete' is an empty schema with no required flag. The description says it concerns an npm package version but does not specify the expected format, such as 'operator@version', nor whether the parameter is mandatory. The agent is left guessing about how to construct the call.

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 clearly identifies the resource (an npm package version) and enumerates the results: license, repository, dependency count, and known vulnerabilities with sources. It is specific and useful, but uses a noun phrase rather than an explicit verb and does not contrast with sibling tools.

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 implies the tool is for investigating a specific npm package version's risk profile, but it gives no explicit conditions for when to use this tool versus alternatives, and no exclusions. The mention of 'a concrete version' offers some context, but not full routing guidance.

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