ListIndexTool

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

With no annotations provided, the description carries full responsibility for disclosing behavior. 'Lists all indices' implies a read-only, non-destructive operation, but it does not explicitly state safety, permission requirements, pagination, or return format. The behavior is simple and apparent, yet lacks explicit disclosure.

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, concise sentence ('Lists all indices in OpenSearch') that is front-loaded and contains no unnecessary information. Every word contributes to the meaning.

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?

Given the tool has no parameters and no output schema, the description adequately conveys the core behavior of listing all indices. It could be more explicit about the return format or whether system indices are included, but for such a simple tool, the description is sufficient.

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 has zero properties, so there are no parameters to document. The description appropriately adds no parameter information, and the baseline for zero-parameter tools is high. No further explanation is needed.

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 uses the specific verb 'Lists' and identifies the resource as 'all indices in OpenSearch', making the tool's purpose immediately clear. This clearly distinguishes it from sibling tools like IndexMappingTool, SearchIndexTool, and GetShardsTool, which serve different purposes.

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 when to use the tool—whenever a list of all indices is needed—but provides no explicit guidance on when not to use it or how it compares to alternatives. There are no exclusions or alternative tool references, so the usage context is only implied.

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