iaas_create_block_device

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

Annotations already declare this as a non-readonly, non-destructive, non-idempotent, open-world mutation. The description adds useful behavioral context about custom property precedence, especially that dataStore takes precedence over storagePolicy, but it does not discuss permissions, failure modes, or other operational behavior.

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 front-loaded with the core action and then lists relevant custom properties efficiently. The trailing POST endpoint is redundant with the annotation title, but the rest is useful and reasonably concise.

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 create mutation with a nested schema and no output schema, the description covers the operation and key custom properties. However, it leaves out auth/prerequisite context and does not describe what happens on success or failure, so it is only minimally complete for an agent to invoke confidently.

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 coverage is 100%, so baseline is 3. The description adds value beyond the schema by documenting four customProperties keys (dataStore, storagePolicy, provisioningType, resourceGroupName) that the schema only describes generically as additional properties, and by stating the precedence rule between dataStore and storagePolicy.

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 a specific verb and resource: 'Create BlockDevice'. It clearly identifies the operation, but does not distinguish it from sibling operations such as iaas_create_block_device_snapshot or iaas_create_machine.

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 explains optional custom properties but gives no explicit guidance on when to use this tool versus alternatives, nor does it mention prerequisites or when-not-to-use conditions.

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