list_availability_zones

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states the action ('list all') but does not describe the return format, potential size of the response, pagination, or error behavior. As a read-only list operation, it is not misleading, but it adds minimal behavioral context beyond the basic action.

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, front-loaded sentence with no unnecessary words or repetition. It is highly concise and well-structured for the tool's simplicity.

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 list tool, the description is sufficient to understand the core function. However, it does not mention what fields or format the returned zones will have, which might be useful for an agent. Given the absence of an output schema and the simplicity of the operation, this is acceptable but not fully complete.

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 takes zero parameters, and the schema coverage is 100% (empty schema). Since there are no parameters to document, the description adds no parameter information, and the baseline of 4 is appropriate. There is nothing missing in parameter semantics.

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 'List all availability zones' uses a specific verb ('list') and resource ('availability zones'), making the purpose immediately clear. It distinguishes itself from the sibling tool 'get_zone_configuration', which fetches details of a specific zone, by indicating this tool returns all zones.

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 (when you need to list all availability zones) but does not explicitly mention alternatives or when not to use this tool. There is no guidance comparing it to sibling tools like 'get_zone_configuration', so the usage context is only implicit.

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