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

Annotations already provide readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds behavioral details beyond this: it returns 1-3 libraries, includes one-line reasoning, and provides an 'honest warning about the top pick.' This is useful context about the tool's conduct and output style.

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 exactly two sentences: the first is dense with purpose and output details, the second is a clear usage directive. No redundant words or repetition of schema/annotation information. It is front-loaded and earns every word.

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 only 2 simple parameters, a rich annotation set, and an existing output schema, the description covers all necessary aspects: what it does, output format, and when to use it. There is no missing critical context like permissions, side effects, or return behavior (covered by schema).

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% (both 'task' and 'ecosystem' have descriptions), so the baseline is 3. The description does not add new parameter semantics beyond the schema, but it reinforces that 'task' is a coding task and that the output recommendations depend on it. It doesn't introduce confusion or omit details.

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 uses a specific verb ('recommend') and resource ('should-i-use index'), and clearly states the output (1-3 libraries with reasoning and warning). It distinguishes itself from siblings like should_i_use (which likely evaluates a specific library) and audit_dependencies (which audits existing dependencies).

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 phrase 'Use before installing anything' provides clear timing/context. It doesn't explicitly name alternatives or exclusions, but the context implies this tool is for pre-installation selection. Sibling names are present but not referenced; a more explicit comparison would push this to 5.

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