list_available_downloads

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

With no annotations, the description carries the disclosure burden. It clearly states the tool lists available versions and that filter narrows results, but it does not mention whether this contacts a remote source, the output format, or any preconditions like pyenv being installed. The behavior is simple and non-destructive, so the lack of additional disclosure is acceptable but not outstanding.

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 two-line description plus one-line Args section is tightly written. Every sentence adds value: the purpose statement is front-loaded and the parameter explanation is detailed enough without 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 tool with one optional parameter and an output schema, the description is nearly complete. It explains what the tool does and exactly how filtering works. The only minor gap is not explicitly placing the tool among its siblings (e.g., that it lists remote/downloadable versions, not installed ones), though the wording already implies this.

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 description provides the full meaning of the only parameter, filter, and gives a concrete example ('3.12' shows only 3.12.x versions), compensating for the schema's lack of a property description. This is unambiguous and directly actionable.

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 ('List') and identifies the exact resource: Python versions available for installation via pyenv. The phrase 'available for installation' distinguishes it from sibling version-listing tools like list_versions, which likely list installed versions.

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 implies the tool should be used when you need to see which Python versions can be installed through pyenv, but it doesn't explicitly state when to prefer it over list_versions or other siblings. No exclusions or alternative conditions are given.

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