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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, destructiveHint. Description adds: fans out across deps.dev and bundlephobia, mentions partial failures ('sources_failed will list it if it times out'), and timing ('first measurement on a new version can take 5-30s'). Also lists return components (summary, per-advisory, links, alternative versions). Adds significant context beyond 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?

Description is detailed but somewhat dense. It front-loads the core purpose and usage guidelines effectively. However, the format is a single block of text; breaking it into paragraphs could improve readability. Still, every sentence adds value and no unnecessary repetition.

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?

Given tool complexity (multi-source, partial failures, two parameters, no output schema), description is complete. It explains the return summary block fields, per-advisory detail, links, alternative versions, and graceful degradation. No output schema is present, so description properly carries the burden of explaining return values.

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 both parameters described. Description adds: 'Scoped packages (e.g. "@types/node") are accepted' for package, and 'Defaults to the latest published version when omitted' for version. Adds useful detail beyond the schema without being redundant.

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?

Description clearly states it is a composite check for npm packages covering license, advisories, version history, and bundle size. The verb 'scan' and resource 'dependency' are specific. It distinguishes from siblings by focusing on npm ecosystem and combining multiple data sources, unlike other tools that target other ecosystems or single sources.

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 says 'Use whenever an agent asks "is X safe / popular / small" or "what does adding lodash cost me".' Also states exclusion: 'PyPI / Maven / Cargo / Go fall under deps.dev:version directly.' Provides clear context for when to use this tool versus alternatives.

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