npm_package_info

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

With no annotations provided, the description must convey behavioral traits. It implies a read-only operation via 'Get' and enumerates what data is returned, but it does not disclose potential error conditions, rate limits, or authentication requirements. This is adequate but not rich.

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 a single, well-structured sentence that lists the tool's capabilities without unnecessary words. It front-loads the core purpose and efficiently communicates the scope.

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?

For a simple single-parameter read tool with no output schema, the description is remarkably complete: it enumerates all major return categories, leaving little ambiguity about what the tool provides. The absence of an output schema is compensated by this detailed enumeration.

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?

The input schema fully describes the only parameter (package_name) with an exact format and examples, giving 100% coverage. The description adds no further semantic value beyond the schema, so the baseline of 3 is appropriate.

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 uses a specific verb ('Get') and resource ('npm package') and lists numerous concrete outputs (versions, dependencies, maintainers, repository, license, size, npm score, weekly downloads). This clearly distinguishes it from sibling tools like npm_search or npm_compare_packages, which focus on other tasks.

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 clearly implies this tool is for retrieving comprehensive details about a specific npm package, providing clear context for when to use it. However, it does not explicitly mention alternatives or state when not to use it, which would earn a 5.

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