r_install_packages

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

No annotations are provided, so the description carries the disclosure burden. It states the source (CRAN), the target (user's R library), and a timing consequence ('can take several minutes for packages that compile'). It does not detail dependency installation or the default skip-if-present behavior, but the core mutation and its cost are clearly disclosed.

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 three short sentences with no wasted words: action and target first, usage trigger second, and an important duration caveat last. Every sentence 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 simple two-parameter installer, the description covers when to use it, what it installs, where it installs, and that it may be slow. The schema fully defines the arguments. Minor gaps such as dependency handling and failure behavior do not make the tool difficult to invoke 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?

Schema description coverage is 100%, with both 'packages' and 'force' already documented in the schema, including the default for force and an example list format. The description adds no parameter-specific meaning beyond what the schema provides, so it remains at the baseline.

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 opens with a specific verb and resource: 'Install R packages from CRAN into the user's R library.' It clearly specifies what the tool does and where packages go, and it is readily distinguishable from the sibling data and analysis tools.

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 gives an explicit trigger: 'Use when a tool reports that a package is missing.' It does not mention exclusions or alternatives, but no sibling tool provides package installation, so the guidance is sufficient for the context.

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