block_storage_list_attached

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

There are no annotations, so the description carries the burden of disclosing behavior. 'List' implies a read-only operation, but this is never stated explicitly. The description adds that it returns volumes 'currently attached' and includes instance information, giving some context. However, it omits key behavioral details like pagination, potential rate limits, or permissions required. A 3 is appropriate for a simple list operation with no annotations.

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 two tight sentences with no filler. It clearly states the primary action and the expected return without redundant phrasing. Every word 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 zero-parameter list tool with an output schema (which presumably documents the return structure), the description is largely sufficient. It states the scope ('all attached volumes') and the inclusion of instance information. The only missing elements are explicit mention that the operation is read-only and a pointer to the sibling tool for unattached volumes, but these are minor given the simplicity of the tool.

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 has zero parameters, and the schema is empty, so there is nothing to document. According to the rubric, a baseline of 4 is justified for 0-parameter tools. The description does not need to add anything beyond confirming no inputs are required, which is implicitly clear from the empty schema.

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 states a specific verb ('List') and resource ('attached block storage volumes') with added detail ('with instance information'). The name and description clearly differentiate from the sibling block_storage_list_unattached, leaving no ambiguity about what this tool returns.

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 does not provide any explicit guidance on when to use this tool versus alternatives. It does not mention that block_storage_list_unattached exists for the complementary use case, nor does it provide any context about filtering or scope. An agent must infer usage from the name alone.

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