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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds valuable behavioral details: partial failures degrade gracefully, bundlephobia's first measurement may take 5-30 seconds, and sources_failed field lists timeouts. No contradictions 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?

The description is comprehensive but not excessively wordy. It front-loads the core purpose and uses concise bullet-like formatting for the return fields. A slightly tighter structure could improve scannability, but it remains efficient.

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?

Despite lacking an output schema, the description fully enumerates the return fields (summary block, per-advisory, links, alternative versions) and explains partial failure behavior. Given the tool's complexity and lack of output schema, this is complete and leaves no critical gaps.

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% with clear descriptions for both parameters. The description adds minimal extra semantics beyond noting that scoped packages are accepted and version defaults to latest. Since schema already provides adequate meaning, baseline 3 is 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?

The description clearly states it's a composite check for assessing whether to add an npm package, covering license, advisories, version history, and bundle size. It succinctly defines the tool's purpose and differentiates it from other tools in the sibling list, none of which are dependency scanners.

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?

Explicitly tells when to use: 'Use whenever an agent asks "is X safe / popular / small" or "what does adding lodash cost me"'. Also clarifies ecosystem scope (NPM v1) and points users to deps.dev:version for other package managers, providing clear guidance and alternatives.

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