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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint true, and destructiveHint false. The description adds significant behavioral context: partial failures degrade gracefully, bundlephobia's first measurement can take 5-30s, and sources_failed list will report 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 relatively long but each sentence adds value: primary purpose, usage guidance, ecosystem scope, fallback behavior, and return format. It could be slightly more concise but is well-structured and informative without being excessive.

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?

No output schema exists, but the description fully describes the return format: a summary block with specific fields, per-advisory detail, links, and alternative versions. It also covers error behavior and timeout scenarios. Together with annotations, the description provides complete context for an agent to use the tool effectively.

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% (both package and version have descriptions). The tool description does not add additional semantic meaning beyond what the schema provides. It mentions 'npm package name' and 'specific version' but these are already in schema. 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 the tool performs a composite check for npm packages covering safety, popularity, and size. It uses the specific verb 'scan' and resource 'dependency', and distinguishes from sibling tools (e.g., deep_research) by specifying the NPM ecosystem scope and the two external data sources (deps.dev, 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?

Explicit usage guidance: 'Use whenever an agent asks "is X safe / popular / small" or "what does adding lodash cost me".' Also clearly states limitations: 'NPM ecosystem only in v1; PyPI / Maven / Cargo / Go fall under deps.dev:version directly.' This provides both when-to-use and when-not-to-use guidance.

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