search_packages

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

With no annotations, the description carries the burden. It discloses that it returns packages with popularity ranking, descriptions, download stats, and quality scores, and that output includes package names and versions. It doesn't explicitly state read-only behavior, but for a search tool this is implied and sufficiently transparent.

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?

Three sentences, each with a distinct purpose: definition, use cases, and output characteristics. No filler or redundant information, highly efficient.

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 two-parameter search tool with no output schema, the description fully covers purpose, usage, and expected output, and even hints at compatibility with compare_packages. It is complete enough for an agent to select and invoke 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 coverage is 100% for query and limit parameters. The description adds context by framing query as a way to 'find libraries' or 'see what's available for a specific task,' but doesn't add new semantic detail beyond the schema descriptions. Baseline 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 states 'Search and discover npm packages' with specific use cases like 'find libraries, compare options, see what's available for a specific task, or answer "what packages exist for X?" questions.' It clearly distinguishes itself from siblings by noting its output can be used as input for compare_packages.

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 this to find libraries, compare options, see what's available for a specific task, or answer "what packages exist for X?" questions.' It also mentions that output can be used as input for compare_packages, providing an alternative and integration guidance.

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