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

Annotations already indicate readOnly, openWorld, idempotent, non-destructive. Description adds detail: composite call fanning out to deps.dev and bundlephobia, returned fields, partial failure handling, and potential latency (5-30s). 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?

Description is front-loaded with purpose, then usage, then output, then notes. Slightly verbose but each sentence adds value. Wordy enough to be clear but could be trimmed slightly.

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 no output schema, the description fully documents the return value (summary block, advisories, links, alternatives). Also explains composite nature, partial failures, and timing, making it complete for an agent to invoke correctly.

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 100% with clear parameter docs. Description adds context: scoped packages accepted, version defaults to latest, and NPM-only limitation, providing marginal additional value beyond the schema.

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 is a composite check for evaluating npm packages, covering license, advisories, bundle size, etc. It specifies the verb 'scan' and resource 'dependency', and distinguishes from siblings by noting that other ecosystems fall under a different tool.

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: when an agent asks about package safety, popularity, or size. Also provides ecosystem limitation (npm only) and mentions alternative for PyPI/Maven/Cargo/Go. Includes behavior on partial failures.

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