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

Discloses important behaviors: bundlephobia first measurement may take 5-30s, partial failures degrade gracefully with a 'sources_failed' list. Annotations already declare readOnly, openWorld, idempotent; 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?

The description is efficient and front-loaded, but slightly dense. Could be split into shorter sentences for easier scanning, but still very effective.

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?

Comprehensively covers input (package name, optional version), behavior (data sources, potential delays, graceful degradation), and output (summary block with specific fields, per-advisory detail, links, alternative versions). No output schema, but return structure is adequately described.

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% for both parameters (package, version). The description adds context beyond schema: mentions scoped packages are accepted and version defaults to latest. This enriches parameter understanding.

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 explicitly states the tool's composite purpose: 'should I add this npm package to my project' check, covering license, advisories, version history, and bundle statistics. It clearly distinguishes itself from other tools by being a one-call aggregate.

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?

Provides explicit when-to-use guidance ('when an agent asks is X safe / popular / small') and when-not-to-use ('NPM ecosystem only; other ecosystems fall under deps.dev:version directly'). This helps the agent choose correctly among siblings.

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