package_snapshot

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

The annotations provide readOnlyHint and openWorldHint, so the read-only nature is already disclosed. The description adds value by stating 'Free, no payment required,' which is a meaningful operational detail, and by listing the exact data points returned. It does not mention potential rate limits or registry availability, but given the annotation coverage, 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?

The description is two sentences long, front-loads the primary purpose, and each sentence adds distinct value: the first clarifies the tool's output, the second addresses a potential user concern (cost). No unnecessary words or repetition.

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 having no output schema, the description explicitly enumerates the return fields (version, license, description, repository, downloads, maintainers, publish date, deprecation status). Combined with the annotations (read-only, open-world) and a clear ecosystem enum in the schema, the description provides a complete and actionable picture of the tool's behavior and results.

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 already provides full descriptions for both parameters (name and ecosystem) with 100% coverage. The tool description mentions the ecosystems and examples like 'express' in the schema, but adds no additional parameter meaning beyond what the schema provides. Thus the baseline score 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 clearly identifies the resource ('a consolidated snapshot of an npm, PyPI or crates.io package') and the scope (a list of eight specific data points). It distinguishes itself from sibling tools like package_vulns and package_downloads by offering a general overview rather than a focused sub-topic.

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 implies usage for obtaining a general package overview, but it does not explicitly mention when to use this tool over alternatives like package_vulns, package_deps, or package_downloads. There is no 'when to use' or 'instead of' guidance, so guidance is reasonable but not explicit.

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