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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive hints. The description adds valuable non-obvious behavioral details: bundlephobia's first measurement can take 5-30s, partial failures degrade gracefully via a 'sources_failed' field, and the specific output fields are listed. 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?

Every sentence earns its place: main purpose, use cases, return summary fields, ecosystem scope, and failure behavior. The description is front-loaded with the core purpose and remains information-dense without wasting words, given the tool's complexity.

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 enumerates the summary block fields, per-advisory detail, links, recent alternative versions, and handles edge cases like timeouts and partial failures. It gives an agent sufficient context to know exactly what will happen and when to use the 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 fully described ('package' and 'version'). The description does not add parameter-specific semantics beyond what the schema already states, e.g., 'Defaults to the latest published version' is already in the schema. 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 clearly identifies a composite npm package evaluation tool with a specific verb ('scan') and resource ('dependency'), explicitly framing it as a 'should I add this npm package' check. It distinguishes itself from any sibling by naming its two data sources (deps.dev and bundlephobia) and the consolidated return.

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?

Provides explicit when-to-use guidance: 'Use whenever an agent asks "is X safe / popular / small" or "what does adding lodash cost me".' It also clearly scopes to the npm ecosystem and directs non-npm ecosystems to 'deps.dev:version directly', which serves as an alternative tool route.

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