Next Available VMID

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds minimal behavioral context beyond that—it doesn't explain how the ID is determined (e.g., whether it scans existing guests, whether it's guaranteed unique, or whether it might return an ID already in use). With annotations covering the safety profile, a 3 is appropriate.

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?

A single, clear sentence with no wasted words. The description is front-loaded with the verb and resource, and there's no extraneous information.

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 tool, the description is mostly complete. However, it doesn't mention what the return value looks like (e.g., an integer) or whether the ID is guaranteed to be free at the moment of creation. Since there's no output schema, a brief note on the return format would improve completeness.

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 has zero parameters, and the schema coverage is 100% (vacuously). The description correctly indicates the tool takes no input and simply returns a value. There's nothing more the description could add about parameters, so the baseline 4 for zero-parameter tools applies.

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 states a specific verb ('Get') and resource ('next available VM/Container ID number'), which clearly identifies the tool's function. It doesn't explicitly differentiate from siblings, but the resource is specific enough that an agent can distinguish it from the many other proxmox 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 implies usage context: it's a read-only lookup for the next available ID, likely used before creating a VM/container. However, it doesn't explicitly state when to use it versus alternatives like proxmox_guest_list or proxmox_create_vm, nor does it mention that it's a prerequisite for creation workflows.

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