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

Annotations already indicate readOnly, openWorld, idempotent, non-destructive. Description adds value by detailing partial failure behavior (bundlephobia timeout), return fields, and graceful degradation. Minor gap: no mention of caching or external calls beyond the description.

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?

Description is a single paragraph but front-loaded with purpose and key details. Every sentence adds value. Could be slightly more structured with bullets, but it remains concise and informative.

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 no output schema, the description lists all return fields (summary block, advisory details, links, etc.) and explains partial failure. This is sufficient for a complex tool with good annotations.

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 covers both parameters fully, so baseline is 3. Description adds semantics: scoped packages are accepted, default version is latest, and version format example. This provides context beyond the 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 states the tool's purpose: a composite check for deciding whether to add an npm package, combining deps.dev and bundlephobia data. It specifies the verb (scan/check), resource (npm package), and distinguishes from other tools by being a one-call composite.

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 guides when to use: 'when an agent asks 'is X safe / popular / small''. Also clarifies scope: 'NPM ecosystem only in v1' and states alternatives for other ecosystems. This helps the agent choose correctly.

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