list_versions

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

No annotations are provided, so the description carries the behavioral burden. 'List' implies a read-only operation and 'installed locally' scopes the behavior, but it does not explicitly state side effects, failure modes, or output characteristics. Since the tool is simple and non-destructive, the description is acceptable but not deeply transparent.

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, front-loaded sentence with no wasted words. It communicates the action, scope, and environment in a compact and scannable way.

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 zero-parameter read-only list operation with an output schema available, the description is complete. It specifies what is listed, where it looks, and which tool ecosystem it belongs to, making it contextually sufficient.

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 tool takes zero parameters and the schema coverage is complete at 100%, so there are no parameter semantics to explain. The baseline score of 4 applies because no parameter documentation 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 uses a specific verb and resource: 'List all Python versions installed locally via pyenv.' It clearly distinguishes this from siblings like list_available_downloads and get_current_version, since it targets installed local versions rather than downloadable or current ones.

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 context is implied through the phrase 'installed locally via pyenv' and the sibling tool list_available_downloads, which suggests when this tool is appropriate. However, there is no explicit statement of when to choose this tool over alternatives or any exclusion criteria.

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