set_hostname

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

The description discloses an important non-obvious behavior: the hostname is only applied on reboot/rebuild. However, with no annotations provided, it leaves other behavioral aspects unaddressed, such as whether the change is reversible or if there are permission requirements. It adds some context but is not comprehensive.

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 concise sentence with a parenthetical that packs essential extra context. Every word contributes meaning and the key action is front-loaded.

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 mutation tool, the description covers the action and the most important behavioral detail (when it takes effect). The absence of an output schema is acceptable since return values are likely obvious. A brief note about immediate vs. post-reboot effects is already included.

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 coverage is 100% and both parameters are described, but the description adds value by clarifying that the hostname is a DNS label, which constrains the accepted format beyond the schema's simple "New hostname." This helps the agent avoid invalid input.

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+resource construction: "Set the VPS hostname." It clearly distinguishes this tool from sibling tools like power_vps or reinstall_vps by naming the exact action and target. The parenthetical adds useful detail about it being a DNS label.

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 makes the tool's use case obvious: it is for changing the VPS hostname. While it does not explicitly mention alternatives or exclusions, there is no overlapping sibling tool that sets hostnames, so the context is clear enough without saying "use this instead of X."

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