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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not mention that this is a read-only operation, that it may hit the npm registry, or that it uses caching (despite the ignoreCache parameter). There is zero behavioral context.

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 under-specified, consisting of a short fragment that does not earn its place. While brevity is generally good, this is too terse to communicate essential information, so it falls short of effective conciseness.

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?

Given no annotations and no output schema, the description is inadequate. It does not explain the return format, clarify what 'available versions' means, or describe any behavior beyond the tool name. For a tool with parameters and a defined purpose, this is a significant completeness gap.

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%: the input schema already documents 'packages' as 'Package names array' and 'ignoreCache' as 'Bypass cache'. The description adds no additional parameter meaning, but the baseline of 3 applies because the schema already covers parameter semantics.

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 'Available versions list' is a noun phrase rather than a clear verb + resource statement. It roughly restates the tool name npmVersions without specifying that it lists versions for npm packages or providing any action verb, making it essentially a tautology.

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?

No guidance is provided about when to use this tool versus its many siblings (e.g., npmLatest, npmDeps, npmCompare). The description is only five words and gives no context, prerequisites, or exclusions.

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