Add Subnet to Network

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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive, open-world mutation, so the safety profile is covered. The description adds nothing beyond that: no mention of which network the required `id` refers to, no note that duplicate or overlapping ranges will be rejected, and no indication of what happens on failure.

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?

One short, front-loaded sentence with no filler. It is efficiently structured, though the terseness is part of why other dimensions are thin.

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?

With no output schema, a 5-parameter mutation, and a required `id` whose referent (network vs. other resource) is not stated, the description is only minimally sufficient. Annotations carry the behavioral load, but an agent still lacks confirmation of what object is being modified and any success/failure semantics.

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 100%, so the enum semantics of `type`, the vswitch_id dependency, and the network_zone example are already documented in the schema. The description adds no parameter meaning of its own; per the high-coverage baseline, a 3 is appropriate.

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?

Specific verb+resource ("Add a subnet") plus the target scope ("to an existing network"), which distinguishes it from siblings like hetzner_delete_subnet, hetzner_add_route, and hetzner_create_network. It does not explicitly name how it differs from hetzner_update_network or hetzner_change_ip_range, but the purpose itself is unambiguous.

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?

No when-to-use guidance, no prerequisites, and no alternatives named. An agent gets no signal about when to add a subnet versus reconfiguring an existing one (hetzner_change_ip_range) or creating a new network (hetzner_create_network).

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