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

The annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable behavioral context: partial failures degrade gracefully, bundlephobia's first measurement can take 5-30s, and sources_failed will list timeouts. 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?

The description is detailed but well-structured, with the main purpose front-loaded. Every sentence adds meaningful information. It could be slightly tightened, but it's not verbose. The structure with examples and edge cases (e.g., timing for new versions) is helpful.

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 completely details the return structure: a summary block with specific fields, per-advisory details, links, and alternative versions. It also explains partial failure behavior and ecosystem limitations. This provides agents with a full picture of what to expect.

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%, so the baseline is 3. The description adds extra value beyond the schema: it mentions that scoped packages like '@types/node' are accepted and that the version parameter defaults to latest. This enriches agent understanding beyond the schema descriptions.

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's composite nature: it combines deps.dev and bundlephobia checks in one call to evaluate whether to add an npm package. It specifies the verb 'scan/check', the resource (npm package), and the scope (license, advisories, bundle size, etc.). This distinguishes it from sibling tools that might handle individual ecosystems or single-source checks.

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?

The description explicitly states when to use: whenever an agent asks about package safety, popularity, size, or cost. It also provides clear exclusions: 'NPM ecosystem only in v1; PyPI / Maven / Cargo / Go fall under deps.dev:version directly.' This gives agents unambiguous guidance on alternatives.

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