install_hmcl

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

With no annotations provided, the description carries the full burden of disclosure. It transparently lists the side effects: downloading from GitHub, running a build script, copying files, and returning paths. The note 'Safe to re-run' adds important idempotency context. It does not mention potential failure modes or network requirements, but the core behavioral traits 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 a single sentence that is front-loaded with the primary intent, then logically walks through the install steps. Every clause adds necessary information—checking, downloading, building, copying, returning, and idempotency—with no filler or redundancy.

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 complex multi-step tool with no parameters and no output schema, the description is remarkably complete: it covers the conditional download, the build command with a prerequisite, the file placement, and the return value. The 'safe to re-run' note enhances completeness. No critical information appears missing.

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?

This tool has zero parameters, so the baseline is 4 per the rubric. The description appropriately focuses on the procedural steps rather than inputs, and the schema has nothing left undocumented. No additional parameter meaning is needed.

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 the specific verb 'Prepare' and the resource 'HMCL directory', then details the exact steps: conditional download, build via node script, and copying artifacts. This clearly distinguishes it from sibling tools like start_hmcl and stop_hmcl, which focus on lifecycle, and check_environment, which validates prerequisites.

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 provides solid usage context by specifying the install/prepare workflow and stating that it is safe to re-run, implying idempotency. It also calls out a key requirement ('requires javac on PATH'). However, it does not explicitly state when to prefer this over alternatives or mention a scenario where it should not be used, so it stops short of a 5.

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