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

Annotations declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavioral context beyond that: only free components install from the public registry, while Pro components are surfaced separately as requiring Eased Pro. It doesn't explain mixed free/Pro input or output shape, keeping it from a 5.

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?

Two sentences, zero filler. The core outcome (one install command) is front-loaded, and the second sentence carries a non-obvious registry constraint that earns its place.

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 one-parameter, read-only tool with no output schema, the description conveys the return type (a single command) and the key registry limitation, which is nearly everything an agent needs. It leaves the mixed free/Pro-slug case unaddressed, a minor gap.

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 100% and the single `slugs` parameter is already documented with an example and constraints. The description's 'components (and their tokens and helpers)' clarifies the scope of the slugs but adds only marginal meaning over the schema, so the baseline 3 applies.

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 states a precise verb+resource: it produces a single `npx shadcn add …` command for the supplied component slugs, distinguishing it in nature from the sibling retrieval/search tools. It doesn't explicitly name a sibling to contrast against, so it falls just short of the top bar.

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?

Usage is implied (call it when you need an install command for components), and the free-vs-Pro caveat hints at a limitation, but there is no explicit when-to-use, when-not, or named alternative among the siblings.

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