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

Beyond annotations (readOnlyHint, idempotentHint, destructiveHint=false), the description adds significant behavioral context: composite call fanning out to two services, returned fields (summary block, per-advisory detail, links, alternatives), and performance caveat (bundlephobia first measurement can take 5-30s). No contradiction 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?

The description is dense yet well-structured. Front-loaded with composite nature and purpose. Every sentence earns its place, covering input, behavior, output, and edge cases without redundancy.

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?

No output schema exists, but description fully explains return structure: summary block with listed fields, per-advisory detail, links, and alternative versions. Also covers failure mode and timing nuance. Complete for a 2-param tool.

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 described. Description adds that scoped packages ('@types/node') are accepted and that version defaults to latest when omitted, providing value beyond schema.

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 clearly defines the tool as a composite check for npm packages, combining deps.dev and bundlephobia. It specifies the exact verb ('scan_dependency'), resource ('npm package'), and scope ('in ONE call'). No sibling tools overlap in purpose.

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 states when to use ('is X safe / popular / small' or 'what does adding lodash cost me') and notes ecosystem restriction ('NPM ecosystem only'). Also mentions alternative approach for other ecosystems ('deals.dev:version directly'). Provides graceful degradation on partial failures.

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