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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It clearly states the operation is PAID, that it adds to an existing project, and enumerates exactly what is returned: the transitive closure, install order, install line, file paths, provider nesting, and runtime rules. It even warns that getting this wrong can fail silently, which is useful behavioral context.

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 dense but every sentence earns its place: the PAID flag, the core action, the full list of return content, the alternative invocation it replaces, the rationale, and the licensing exception. It is front-loaded with the most important facts and contains no filler.

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 has no output schema and no annotations, the description compensates thoroughly by explaining both what the tool does and exactly what it returns. For a single-parameter tool, it covers installation semantics, return contents, failure risks, and licensing conditions, leaving no major gap for an agent to call it 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 schema already provides 100% coverage for the only parameter, slug, including an example. The description does not add new parameter-specific meaning, but no compensation is needed because the schema already fully documents it. This matches the baseline for high 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 names a specific verb ('Add'), a specific resource ('one component'), and a target context ('existing project'), so an agent knows exactly what action is performed. It also distinguishes this tool from a file-fetching alternative by saying 'Use this instead of fetching /r/*.json by hand'.

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 explicitly tells the agent when to prefer this tool over manually fetching component JSON, and explains why: a component is a closure, not a file. It also gives a licensing exception for foundation components. It does not explicitly contrast with every sibling such as add_screen or emit_app, 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.