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 (can query external data), and idempotentHint=false (results may vary). The description adds minimal context about the optional limit parameter but doesn't disclose important behavioral traits like rate limits, authentication needs, result format, or pagination. With annotations covering safety and scope, this earns a baseline score.

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 extremely concise at just 7 words, front-loading the core purpose ('Search for NPM packages') and efficiently noting the optional parameter. Every word earns its place with zero redundancy or wasted space.

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 (search operation with 2 parameters), rich annotations (covering safety and scope), and 100% schema coverage, the description is minimally adequate. However, with no output schema and many sibling tools, it lacks context about result format, search scope, or differentiation from alternatives, leaving gaps for an agent.

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 clear documentation for both parameters (query and limit). The description mentions 'optional limit' but adds no semantic meaning beyond what the schema already provides about parameter purposes, constraints, or usage examples. This meets the baseline for high schema coverage.

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 action ('Search for NPM packages') and resource ('NPM packages'), making the purpose immediately understandable. However, it doesn't differentiate this search tool from other NPM-related sibling tools like 'npmTrends' or 'npmQuality', which might also involve searching or analyzing packages in different ways.

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 many sibling tools available (e.g., 'npmTrends', 'npmQuality', 'npmVulnerabilities'), there's no indication of whether this is the primary search tool, what types of searches it performs, or when other tools might be more appropriate for specific needs.

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