npm_downloads

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, establishing a safe read operation. The description adds value by specifying the accepted period formats including custom date ranges, which is behavioral context beyond the annotations. It does not describe error handling or response structure, but the annotations lower the bar.

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, well-structured sentence that front-loads the primary action and then provides the period options in parentheses. Every word is informative with no redundancy or fluff.

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?

The tool is simple with two parameters and strong annotations, so the description covers the essential purpose and period options. It does not state the return format, but 'total download count' reasonably implies a numeric result. The lack of a return format description is a minor gap in an otherwise complete description for this tool's complexity.

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%, so the schema already documents the 'name' and 'period' parameters fully. The description repeats the period value examples but does not add new meaning beyond the schema. It reinforces that the result is a total count, but that is purpose, not parameter semantics.

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 tool's purpose with a specific verb ('Get'), resource ('total download count for a package'), and scope ('over a period'). It also enumerates acceptable period values, which helps distinguish it from siblings like npm_downloads_bulk (multiple packages) and npm_version_downloads (version-specific counts).

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 implies usage for single-package download statistics by saying 'for a package', but it does not explicitly state when to use this tool over siblings such as npm_downloads_range or npm_downloads_bulk. No alternatives or exclusions are mentioned, so the guidance is implied rather than explicit.

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