NPM Sentinel MCP

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

Annotations already indicate readOnlyHint=true, openWorldHint=true, and idempotentHint=false, covering safety and scope. The description adds minimal context by specifying 'known vulnerabilities' but doesn't disclose behavioral traits like data sources (e.g., OSV.dev as hinted in the annotation title), rate limits, or error handling, so it provides some value but not rich details.

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 a single, direct sentence with no wasted words, efficiently conveying the core function. It's appropriately sized and front-loaded, making it easy to parse quickly.

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 tool's moderate complexity (checking vulnerabilities), annotations provide good coverage (read-only, open-world), but there's no output schema to explain return values. The description is minimal and doesn't compensate for missing output details or deeper context, making it adequate but with clear gaps in completeness.

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 description coverage is 100%, with the parameter 'packages' clearly documented as 'List of package names to check for vulnerabilities'. The description doesn't add meaning beyond this, such as format examples or constraints, so it meets the baseline for high schema coverage without extra insights.

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 'Check for known vulnerabilities in packages' clearly states the verb ('Check') and resource ('vulnerabilities in packages'), making the purpose understandable. However, it doesn't explicitly differentiate from sibling tools like 'npmDeprecated' or 'npmQuality', which might also relate to package safety or status, so it misses full sibling distinction.

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?

The description provides no guidance on when to use this tool versus alternatives. With siblings like 'npmDeprecated' or 'npmQuality' that might overlap in assessing package risks, there's no indication of specific contexts, exclusions, or comparisons, leaving usage ambiguous.

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