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

Annotations already declare readOnly, idempotent, and non-destructive behavior; the description adds useful context by naming sources (OSV.dev, deps.dev, npm registry), the wrapper relationship, and the returned signals. It repeats some annotation content but contributes beyond it.

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?

Purpose and usage are front-loaded and the structure is logical. It is slightly verbose due to repeating annotation facts and including a lengthy report_feedback fallback sentence, but every section serves a purpose.

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?

With an output schema present and annotations covering safety, the description supplies the remaining context: npm scope, sources, return fields, and the non-npm alternative. An agent has enough to select and invoke the tool correctly.

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%, but the description adds meaning by clarifying that package_name is an npm package name and that version is optional with latest resolved if omitted. This goes beyond the schema's basic examples.

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?

States it produces a SHIP/CAUTION/BLOCK risk brief for npm packages with frontend-specific context, and explicitly names the wrapped sibling security_fetch_package_risk_brief. This clearly distinguishes it from the general package risk tool.

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 instructs to use security_fetch_package_risk_brief for non-npm ecosystems, and frames this tool as npm-restricted with frontend-specific signals. It also provides a report_feedback fallback when the response does not serve the user's need.

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