NPM Sentinel MCP

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

Annotations provide readOnlyHint=true, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds value by specifying 'quality metrics' as the focus, which hints at non-destructive analysis of package attributes. It doesn't contradict annotations and adds context about the type of analysis, though more detail on metrics (e.g., scoring, maintenance indicators) would improve 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?

The description is a single, efficient sentence: 'Analyze package quality metrics'. It's front-loaded and wastes no words, though it could be more informative. It's appropriately sized for a simple tool but lacks depth that might be needed given the context.

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 complexity (simple analysis with one parameter), annotations cover safety and idempotency, and schema fully describes the input. However, with no output schema and many sibling tools, the description is minimal and doesn't explain what 'quality metrics' include or how results are returned. It's adequate but has clear gaps in guiding usage and output expectations.

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 'packages' parameter clearly documented as 'List of package names to analyze'. The description adds no additional parameter semantics beyond this. It doesn't explain format constraints, size limits, or handling of invalid inputs. Baseline 3 is appropriate since the schema fully describes the parameter.

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 'Analyze package quality metrics' states a general purpose but lacks specificity. It mentions 'analyze' (verb) and 'package quality metrics' (resource), but doesn't clarify what 'quality metrics' entail or distinguish it from siblings like npmScore or npmMaintenance. It's vague about scope and measurement criteria.

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?

No guidance is provided on when to use this tool versus alternatives. With many sibling tools (e.g., npmScore, npmMaintenance, npmVulnerabilities), the description offers no context about when this analysis is appropriate, what it covers, or when to choose other tools. Usage is implied but not specified.

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