Check a single package's status

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

With no annotations, the description carries the full burden. It discloses the read-only nature via 'Look up' and 'reports', and lists the specific data returned (version, range lag, deprecation, license). It does not mention error behavior or rate limits, but for a simple lookup this is adequate.

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?

Two sentences, no wasted words. The first sentence front-loads the core purpose and outputs; the second provides usage guidance. Every phrase earns its place.

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?

The tool is simple (2 params, no output schema), and the description covers all essential return values, usage context, and alternatives. It is fully self-contained for selecting and invoking the tool correctly.

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%, but the description adds meaning by explaining how the 'range' parameter works ('how far a given range/version is behind') and provides usage examples. This exceeds the baseline of 3 by giving context beyond the 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 states a specific verb ('Look up') and resource ('one npm package'), and lists concrete outputs: latest version, range comparison, deprecation status, and license. It explicitly contrasts with 'single package' vs. the sibling 'audit_dependencies', making the distinction clear.

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?

It provides explicit usage context: 'Use for a quick one-off check... without needing a whole package.json.' This implies when to use this tool over a bulk audit, though it doesn't name the alternative explicitly. The exclusion ('without needing a whole package.json') gives practical guidance.

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