sizeReturn the publish size and full install size (including dependencies) in bytes for an npm package name and optional version via packagephobia.com.
| Name | Required | Description | Default |
|---|---|---|---|
| package | Yes | npm package name (scoped allowed) | |
| version | No | Specific version (default latest) |
| Name | Required | Description | Default |
|---|---|---|---|
| package | No | npm package name | |
| version | No | Package version | |
| installSize | No | Install size in bytes | |
| publishSize | No | Publish size in bytes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so description adds value by explaining the tool queries packagephobia.com and returns sizes in bytes including dependencies. No contradictions with annotations.
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?
Single sentence with no redundancy. Front-loaded with key information about what is returned and from where.
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 the simple tool with 2 well-documented parameters, rich annotations, and an output schema (exists), the description fully covers what the tool does without missing critical information.
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%, with both parameters having descriptions. The description adds minimal parameter-specific meaning beyond restating that version is optional and default is latest. The mention of 'packagephobia.com' provides external context but not 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?
Description explicitly states verb 'Return', resource 'publish size and full install size', and source 'npm package name and optional version via packagephobia.com'. It clearly distinguishes itself from sibling tools, none of which perform this specific function.
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?
Description does not provide explicit guidance on when to use this tool versus alternatives. While the tool's purpose is clear, there is no mention of prerequisites, when to avoid, or related tools. However, given its unique function, the need for such guidance is lower.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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