Update Guest Configuration

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description's job is lighter. The description adds the 'requires elevated permissions' context and the delete parameter explicitly clarifies it removes config keys, not the VM. This adds meaningful behavioral context beyond the annotations.

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 that front-loads the action and resource, with the type constraint and permission requirement appended. It earns its place without redundancy, though it could be slightly more structured with explicit when-to-use guidance.

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 mutation tool with no output schema, the description plus annotations cover the key aspects: what it does, that it is destructive, that it is idempotent, and that elevated permissions are needed. The main gap is not explaining the effect of the config object on existing settings (merge vs replace), but the pointer to proxmox_guest_config partially mitigates 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?

Schema description coverage is 80%, so the schema already documents most parameters. The description adds value by clarifying the delete parameter's semantics ('Does NOT delete the VM') and by pointing to proxmox_guest_config for valid keys. The config parameter's free-form object nature is partially compensated by that pointer.

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 ('Update') and resource ('VM/LXC config key-value pairs'), and distinguishes the target type (vm|lxc). It is clear enough to separate from sibling tools like proxmox_guest_config (read) and proxmox_guest_delete (delete VM), though it does not explicitly name those alternatives.

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 is for updating config key-value pairs on a VM or LXC, and the config parameter description points to proxmox_guest_config for discovering valid keys. However, it does not explicitly state when to use this tool versus alternatives like proxmox_guest_pending or proxmox_guest_config, nor does it mention prerequisites beyond elevated permissions.

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