compare_packages

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, and openWorldHint, which the description does not contradict. The description adds that the tool returns table-shaped JSON with one row per package, providing useful behavioral context. It could mention ordering or error handling but is sufficient.

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 two sentences plus concise 'USE WHEN' and 'RETURNS' hints. Every part adds value, and the main action is front-loaded. No redundant or unnecessary words.

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 (2 parameters, no output schema, no nested objects), the description covers purpose, usage, and output format. It does not mention error handling or edge cases, but the annotations provide safety cues. Overall, it is sufficient for an agent to invoke correctly.

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 description reinforces the ecosystem parameter (same ecosystem) and the packages parameter (2-10 packages). The schema already includes an example for packages and an enum for ecosystem. The description adds clarity by linking the parameters to the comparison context, exceeding 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 tool performs a side-by-side comparison of packages, listing specific attributes (health, vulns, downloads, etc.) and specifies the range 2-10 packages in the same ecosystem. This distinguishes it from sibling tools like check_package (single package) or find_alternatives.

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 includes explicit 'USE WHEN' guidance for comparative queries ('X vs Y' / 'should I pick X or Y'), making the intended usage clear. It does not explicitly exclude single-package checks, but the context of siblings and the tool's name imply that.

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