npmTrends

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

Annotations already declare readOnlyHint and idempotentHint, so the description's statement 'Get download trends' is consistent. However, the description adds no behavioral context beyond what annotations provide, such as caching behavior (though the 'ignoreCache' parameter exists) or rate limits. With good annotations, a score of 3 is appropriate – the description is adequate but not informative.

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, clear sentence that efficiently conveys the tool's purpose. It is front-loaded and contains no unnecessary words. However, it could be slightly more structured (e.g., mentioning the primary parameter), but for a simple tool, it is highly concise.

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 (3 parameters, output schema exists, good annotations), the description is minimally complete – it states the purpose. However, it does not clarify that the tool fetches data from npm trends or mention constraints like the 25-package limit (covered in schema). It is adequate but not exemplary.

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?

Input schema coverage is 100%, so the schema already describes all three parameters (packages, period, ignoreCache) with definitions and defaults. The description adds no additional meaning or context about parameters. Baseline 3 is correct when the schema bears the load.

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 'Get download trends and popularity metrics for packages' clearly states the tool's function: retrieving download trend and popularity data for packages. It uses a specific verb ('Get') and resource ('download trends and popularity metrics'), and it distinguishes this tool from siblings like npmVersions, npmDeps, etc., by focusing solely on trends and popularity.

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 the many sibling tools (e.g., npmScore, npmQuality). There is no mention of prerequisites, typical use cases, or when not to use it. An agent would not know what distinguishes this from other npm analysis tools without further context.

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