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

Annotations already declare readOnlyHint, idempotentHint, etc. Description adds rich behavioral context: composite nature, partial failures, bundlephobia first measurement delay (5-30s), sources_failed list. No contradiction.

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 front-loaded with purpose and packed with details. Every sentence adds value, but could be slightly more concise. However, it efficiently conveys all necessary information in a dense paragraph.

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 composite tool with no output schema, the description thoroughly explains return fields (summary block, per-advisory detail, links, alternative versions), limitations (NPM only, bundlephobia delay), and error handling (sources_failed). Complete given complexity.

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 has 100% description coverage for both parameters. Description adds value beyond schema: 'Scoped packages (e.g. @types/node) are accepted' and 'Defaults to the latest published version when omitted'.

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 uses a specific verb 'scan' and resource 'dependency', clearly stating it is a composite check for npm packages. It distinguishes from sibling tools (e.g., deep_research, entity_profile) by focusing on npm ecosystem and combining deps.dev and bundlephobia.

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 states when to use: 'whenever an agent asks is X safe / popular / small' or 'what does adding lodash cost me'. Also provides exclusion ('NPM ecosystem only in v1') and alternatives ('PyPI / Maven / Cargo / Go fall under deps.dev:version directly').

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