list_indices

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

No annotations are provided, and the description only mentions the returned fields. It does not disclose any behavioral traits such as whether the 'pattern' parameter filters results, what the default behavior is, or any auth requirements. For a read operation, this is minimal.

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 extremely concise (one line), which is appropriate for a simple tool, but it lacks structure. It is front-loaded with the verb and resource, but the brevity comes at the cost of omitting parameter details.

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?

The tool has an output schema (not shown here), so the description does not need to detail return values, but it does mention them. However, it fails to describe the only input parameter, making the description incomplete for effective use.

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 0% description coverage, and the description does not mention the 'pattern' parameter at all. The agent has no semantic information about what this parameter does, despite it being the only parameter. This is a critical gap.

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 clearly states that the tool lists indices and specifies the returned fields: name, health, status, and doc count. This distinguishes it from sibling tools like 'index_mapping' and 'cluster_health'.

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 implicitly suggests using this tool when you need a list of indices with basic health and status info, but it does not explicitly state when to use it versus alternatives like 'index_mapping' for mappings or 'cluster_health' for cluster health.

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