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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds substantive context beyond that: the returned command bundles shared foundation tokens and Arc dependencies plus setup notes, and Pro items are gated by an Arc Pro token on the connection. It does not describe output format details, 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?

Two sentences, front-loaded with the core purpose and artifact. Dense but every clause adds real information (bundled dependencies, setup notes, Pro gating); no filler or restatement of the title.

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 read-only, idempotent, two-parameter tool with no output schema, the description explains what the tool returns (CLI command plus setup notes) and the availability gating. The only notable omission is any mention of the `runner` parameter, which is left entirely to the enum.

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 50%. The description accounts for the required `ids` parameter ('one or more Arc components or blocks', matching minItems: 1), but the `runner` enum (npx/pnpm/yarn/bun) is undocumented in both the schema and the description. Baseline 3 is appropriate given the schema carries part of the load.

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 specific verb (Get) and a specific artifact (the shadcn CLI install command), and enumerates what the command carries (foundation tokens, Arc dependencies, setup notes). This is clearly distinguishable from sibling readers like get_component, get_skill, list_components, and search_components, which do not return an install command.

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: use it when you need an install command for one or more components/blocks. It adds a real gating condition (Pro registry items require the connection to carry a Pro token), but it never states when to prefer this over get_component or search_components, nor any explicit when-not guidance.

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