compare_packages

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true. The description adds the return format (table-shaped JSON) and the dimensions compared, but does not detail potential behaviors like rate limits or data source freshness. This is adequate given the safety annotations.

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, front-loaded with purpose, and every part adds value: the comparison attributes, the package range, and the use trigger and return type. No waste.

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?

For a tool with two parameters and no output schema, the description covers the main aspects: what it compares, when to use it, and the general return format. It lacks details on exact JSON fields or error cases, but the listed attributes give sufficient context for typical usage.

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 coverage is 50% (only 'packages' has a description). The description adds the semantic constraint 'same ecosystem', clarifying the relationship between parameters, but does not explain the ecosystem enum or the output structure beyond mention of table-shaped JSON. This partially compensates but not fully.

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 it performs a side-by-side comparison of 2-10 packages, listing specific attributes (health, vulns, downloads, maintainers, last release) and the 'same ecosystem' constraint. 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?

Provides explicit when-to-use guidance ('USE WHEN: X vs Y / should I pick X or Y'). Does not mention when not to use or alternatives, but the use case is clearly scoped.

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