hcloud_list_availability_zones

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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is covered. The description adds only the ECS scope; it says nothing about error behaviour for an invalid region, whether zones are region-scoped at all, or what the response contains.

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 six-word sentence with the service scope in the right place and no filler. It is terse but not padded or rambling.

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 and no annotations explaining return shape, the description should at least indicate that it returns a set of zone identifiers tied to the supplied region. For a discovery helper whose output feeds other calls, this is under-explained.

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?

There is a single parameter with 100% schema description coverage, so the schema already documents the one input. The description does not add format examples, case sensitivity, or how region names map to availability zone identifiers, so baseline 3 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?

"List availability zones for ECS" gives a specific verb (list) and resource (availability zones) and scopes it to the ECS service, which distinguishes it from hcloud_list_dcs_available_zones. It stops short of explaining what an availability zone means in this cloud, but the operation is identifiable.

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?

There is no guidance on when to call this versus alternatives, whether the region must already exist, or what the result is used for (e.g., selecting a region for a later ECS create call). The agent must infer all of that from the name.

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