block_storage_list_by_region

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

With no annotations provided, the description must carry the behavioral disclosure burden. It states it will return a list of volumes in the region, which clearly implies a read-only list operation. However, it does not explicitly say the operation has no side effects, nor does it cover pagination or error behavior. For a simple list tool, the core intent is conveyed, but many behavioral details are left unstated.

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 compact: a single sentence for the purpose, followed by structured Args and Returns sections. There is no filler, and the structure makes the parameter meaning and return value easy to scan. It could be even more succinct, but it already earns its place.

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 one-parameter tool, the description covers the primary operation, the parameter meaning including examples, and the return value. An output schema is present, so the Returns description is sufficient. Minor gaps exist (e.g., pagination, behavior when region is invalid), but the overall context is enough for a confident invocation.

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 input schema only declares 'region' as a string, with no description (0% schema coverage). The tool description fully compensates by explaining the parameter as 'Region code to filter by' and listing concrete examples ('ewr', 'lax', 'fra'), which gives the agent the necessary semantic context to supply a valid value.

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 opens with 'List block storage volumes in a specific region,' clearly identifying the action (list), resource (block storage volumes), and scope (region). This differentiates it from sibling tools like block_storage_list_unattached and block_storage_list_attached, which filter by attachment state instead of region.

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 provides no guidance about when to use this tool versus alternatives. It does not mention block_storage_list_unattached, block_storage_list_attached, or any other list variants, and gives no context about when region-based filtering is the correct choice. Usage guidance is left entirely implicit.

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