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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, destructiveHint=False. Description adds significant context: NPM-only v1, partial failures degrade gracefully, bundlephobia first measurement can take 5-30s, sources_failed list included. 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 thorough but not overly verbose; each sentence adds value. It is front-loaded with the core purpose. However, the length could be slightly trimmed without losing information, hence 4 instead of 5.

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 explains the return value structure (summary block with key metrics, per-advisory detail, links, alternative versions) and handles edge cases (partial failures, timing). This is complete for a composite tool with good annotations.

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 descriptions for both parameters. The description adds that scoped packages (e.g., '@types/node') are accepted and that version defaults to the latest published when omitted, enhancing clarity beyond 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's a composite check for adding an npm package, covering license, advisories, version history, bundle size, dependency count, ESM/tree-shake support. It distinguishes from other tools by specifying ecosystem scope (NPM only v1) and mentions alternatives for other ecosystems.

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"'. Provides guidance on alternatives (deps.dev:version directly for other ecosystems) and handles partial failures with timing details.

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