NPM Sentinel MCP

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

Annotations already provide key behavioral hints: readOnlyHint=true (safe operation), openWorldHint=true (handles unknown packages), and idempotentHint=true (repeatable). The description adds minimal context by implying it checks deprecation status, but doesn't disclose details like rate limits, error handling for invalid packages, or output format. Since annotations cover core traits, the description adds some value but lacks rich behavioral 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, efficient sentence: 'Check if packages are deprecated'. It's front-loaded with the core action and resource, with zero wasted words. This makes it easy to scan and understand quickly, fitting the tool's simple purpose perfectly.

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 low complexity (one parameter, no output schema) and rich annotations, the description is minimally adequate. It states the purpose but lacks details on output (e.g., deprecation status format) and usage context. For a read-only, idempotent tool with good annotations, it meets basic needs but could be more informative about results and integration with sibling tools.

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?

The input schema has 100% description coverage, with the 'packages' parameter clearly documented as 'List of package names to check for deprecation'. The description doesn't add any extra meaning beyond this, such as examples of package names or formatting requirements. With high schema coverage, the baseline score of 3 is appropriate, as the schema handles parameter documentation adequately.

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 if packages are deprecated' clearly states the verb ('Check') and resource ('packages'), specifying the action of verifying deprecation status. It distinguishes from siblings like 'npmAlternatives' or 'npmVulnerabilities' by focusing solely on deprecation, but doesn't explicitly contrast with similar tools like 'npmMaintenance' or 'npmQuality' that might overlap in assessing package health.

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. It doesn't mention scenarios like checking before installing packages, comparing with 'npmVulnerabilities' for security risks, or using 'npmMaintenance' for broader health checks. Without such context, users might struggle to choose between this and sibling tools.

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