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

Annotations already indicate read-only, idempotent, open world. The description adds that bundlephobia's first measurement can take 5-30s, partial failures degrade gracefully, and lists sources_failed. 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?

Well-structured with front-loaded purpose, but somewhat lengthy with detailed return format and edge cases. Every sentence adds value, but could be slightly more concise without losing meaning.

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 no output schema, the description thoroughly explains return fields (summary block fields, per-advisory detail, links, recent alternative versions) and covers behavioral details like timeouts and partial failures. Complete for a composite check tool.

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 (package name with scoped package mention, version with default to latest). The description adds only marginal extra context (e.g., 'NPM ecosystem only' for package parameter). Baseline 3 is appropriate as schema already does heavy lifting.

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 npm package evaluation, listing specific data sources (deps.dev, bundlephobia) and return fields. It distinguishes itself from siblings by being the only tool in the list focused on dependency analysis.

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 specifies NPM ecosystem only and directs users to deps.dev:version for other ecosystems, providing clear 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.